The Project Gutenberg eBook of Comments on the Taxonomy and Geographic Distribution of North American Microtines, by E. Raymond Hall and E. Lendell Cockrum

Comments on
the Taxonomy and Geographic Distribution
of North American Microtines

In preparing maps showing the geographic distribution of North American microtines, conflicting statements in the literature and identifications that, if accepted, would result in improbable geographic ranges have led to the examination of pertinent specimens with the results given below. The studies here reported upon were aided by a contract between the Office of Naval Research, Department of the Navy, and the University of Kansas (Nr 161-791), by funds provided by the University of Kansas from its Research Appropriation, and by grants for out-of-state field work from the Kansas University Endowment Association. Grateful acknowledgment is made to persons in charge of the collections at each of the following institutions for permission to use the collections under their charge: Biological Surveys Collection, United States National Museum (herein abbreviated USBS); California Museum of Vertebrate Zoology (MVZ); Chicago Natural History Museum (CNHM); University of Kansas Museum of Natural History (KU); Museum of Comparative Zoology (MCZ); United States National Museum (USNM); Department of Economic Zoology, University of Wisconsin (UWDEZ); and Zoological Museum, University of Wisconsin (UWZM).

When Bole and Moulthrop named Synaptomys cooperi saturatus , with type locality in Illinois, they, in effect, divided the geographic range of Synaptomys cooperi stonei into two parts (see A. B. Howell, N. Amer. Fauna, 50:10 (fig. 2), August 5, 1927) since Bole and Moulthrop ( op. cit. ) did not assign to any subspecies the specimens from southern Wisconsin that Howell ( op. cit. ) had identified as S. c. stonei . Bole and Moulthrop's inclusion in their newly named subspecies of a specimen from as far west as East Columbia, Missouri, left in doubt the subspecific identity of specimens from Iowa and a specimen from Arkansas. Howell ( op. cit. ) had assigned this material from Iowa and Arkansas to S. c. gossii .

Howell recognized that the one individual (168266 USBS) from Lake City, Arkansas, was too young to be identified to subspecies with certainty and assigned the specimen to S. c. gossii "upon geographical grounds" ( op. cit. :19). Keith R. Kelson and one of us (Hall) compared this specimen with pertinent materials. As a result of this comparison we refer the specimen, on the same grounds employed by Howell, to Synaptomys cooperi saturatus .

Specimens from approximately the southern half of Wisconsin (from Kelly Lake southward) were referred to S. c. stonei by Howell ( op. cit. :16). Now that S. c. saturatus has been recognized, these specimens from southern Wisconsin would be expected to be referable to S. c. saturatus . When these specimens were examined and compared (by Hall and Kelson) with other specimens in the United States National Museum the skulls were found to be much larger than in S. c. cooperi , smaller than in S. c. gossii , and nearly the size of those of Synaptomys cooperi saturatus , to which subspecies we refer the specimens in question.

Howell ( op. cit. :16) referred a specimen from Cassopolis, Michigan, a locality that might be presumed to fall within the range of the more recently named S. c. saturatus , to S. c. stonei . Bole and Moulthrop did not mention this specimen when they described and named S. c. saturatus (1942). Neither did Burt, but Cassopolis is within the geographic range ascribed to S. c. cooperi on his map (The Mammals of Michigan, Univ. Michigan Press, p. 213, 1946). Examination (by Kelson and Hall) of the specimen (41777 MCZ) reveals that it resembles S. c. cooperi in shortness of hind foot (18 mm.), shortness of tail (18 mm.), narrowness across zygomata (16 mm.), and grayish pelage. In the long braincase, heavy rostrum, greater condylobasilar length, greater lambdoidal breadth, long rostrum, and longer incisive foramina, it agrees closely with specimens of S. c. saturatus , to which subspecies we refer the specimen.

Necker and Hatfield (Bull. Chicago Acad. Sci., 6:54, 1941) referred specimens from Rosiclaire, Illinois, to S. c. gossii . These specimens were not mentioned by Bole and Moulthrop ( op. cit. ) when they named S. c. saturatus although the specimens presumably would be referred to the newly-named subspecies. We have examined the pertinent specimens (Nos. 15781-15786 and 16049-16054 CNHM) and find that on the basis of dark color, long and slender skull, heavy incisors, and small cheek-teeth, they are referable to S. c. saturatus Bole and Moulthrop. None, however, has a tail so short as the type of S. c. saturatus . For that matter, the average length of the tail of six near topotypes (5 mi. W, 2½ mi. S Monticello, Piatt County, Illinois, Nos. 32037-32042 KU) exceeds that of the type (17.4 mm., range 12-20, as compared to 14 mm. for the type).

In view of the taxonomic treatment accorded by Bole and Moulthrop (Sci. Publs. Cleveland Mus. Nat. Hist, 5:149-151, September 11, 1942) to the lemming mice of the species Synaptomys cooperi , as explained in the preceding account, it has seemed desirable to examine Iowan specimens of this species. Hall and Kelson examined the necessary material and made the following conclusions. An adult male from Hillsboro (168453 USBS) has the lighter color and large skull of S. c. gossii to which Howell (N. Amer. Fauna, 50:19, August 5, 1927) referred the specimen. The more western specimen from Knoxville, a young male (190358 USNM), is almost exactly the same age as a male of S. c. saturatus from Bascom, Indiana (143701 USNM), and is but slightly older than a male S. c. gossii from Ft. Leavenworth, Kansas (91583 USBS). The upper molariform tooth-row is the same length in the specimens from Kansas and Iowa, but is longer in that from Indiana. The fact that the specimen from Knoxville closely resembles the Kansan specimen in other dimensions of the skull, which is larger than in the specimen from Indiana, gives a basis for applying the name Synaptomys cooperi gossii to the specimen from Knoxville. This is the same name recently used by Fichter and Hansen (Bull. Univ. Nebraska State Mus., 3(2):2, September, 1947) for the Iowan specimens, although they seemingly applied the name without being aware of Bole and Moulthrop's earlier naming of S. c. saturatus (Sci. Publs. Cleveland Mus. Nat. Hist., 5:149, September 11, 1942).

Howell (N. Amer. Fauna, 50:30-31, August 5, 1927) had only eight specimens of this subspecies available when he revised the genus Synaptomys . Of these eight (Maine: Mount Katahdin, 2; New Brunswick: Near Bathurst, 1; New Hampshire: Fabyans, 1, the type; Quebec: St. Rose, 4), only the type and one of the specimens from St. Rose are adults. Concerning the others, Howell wrote ( op. cit. :31): "The example from near Bathurst is not adult and has a damaged skull, so is identified provisionally. All other specimens are too young for positive diagnosis."

Since Howell's revision only one additional specimen has been reported. Anderson (Ann. Rept. Provancher Soc. for 1939, p. 71, 1940) reported it from Table Mountain, 3888 ft., Gaspé County, Quebec.

In the collection of the University of Kansas Museum of Natural History there is still another specimen. It is an adult male topotype (No. 6483 KU, formerly No. 72 in the collection of Alfred E. Preble) obtained on August 21, 1905, at Fabyans, New Hampshire. The measurements of this specimen are as follows (measurements in parenthesis are those of the type as given by Howell, op. cit. ): Total length, 135 (132); tail, 26 (24); hind foot, 22 (20); condylobasilar length, 25.1 (25.8); rostral length, 6.5 (6.8); rostral breadth, 4.7 (4.9); interorbital breadth, 3.3 (2.8); zygomatic breadth, 15.4 (16.0); lambdoidal breadth, 12.1 (12.4); incisive foramina, 5.9 (5.7); height of skull, 9.1 (9.3).

Howell ( op. cit. :30) characterized S. b. sphagnicola as: "Large and high [skull] with narrow interorbital sharply ridged, the ridges of the type being joined for a distance of 4 millimeters; interparietal narrow and rectangular. The rostrum is long, tapering very little, and the nasals, slightly constricted medially are quite narrow posteriorly. The incisive foramina are long and wide." Howell further stated ( op. cit. :30-31) that: "It is hard to predict what will be found to constitute the most valuable cranial characters in distinguishing this race from adult medioximus . The discernible differences now are in the shape of the interparietals, rostral characters, and interorbital differences that will probably not hold good when animals of the same age are compared."

As can be seen from a comparison of the measurements given above for the type and the topotype, some of the characteristics given by Howell are not found in the topotype: The interorbital region is not narrow (in fact it is wider than it ordinarily is in some other subspecies of Synaptomys borealis ) and the incisive foramina are not longer than in other subspecies of Synaptomys borealis .

As far as present material permits us to judge, Synaptomys borealis sphagnicola is characterized, cranially, by: Skull large; interorbital region sharply ridged (the ridges being joined for a distance of 4 mm. in the type and of 4.5 mm. in the topotype); rostrum long, tapering relatively little; nasals slightly constricted medially and unusually narrow posteriorly; interparietal narrow and rectangular.

Prior to 1935 caurinus was considered to be a monotypic species. In 1935 Racey and Cowan (Rept. British Columbia Provincial Museum for 1935, pp. H 25-H 26) examined material from southwestern British Columbia of C. caurinus , including a series of 24 specimens from Alta Lake, and compared it with Clethrionomys gapperi occidentalis and C. g. saturatus . They found caurinus to be distinct from C. g. saturatus but were "not convinced that occidentalis and caurinus both merit systematic recognition; should they prove to be indistinguishable, as the little available material indicates, occidentalis will take precedence on grounds of priority. It is our opinion that further study of the distribution of the genus in British Columbia will lead to the recognition of occidentalis as the form inhabiting coast-line and saturatus the interior of British Columbia" p. H 26. In the face of these opinions Racey and Cowan nevertheless recognized caurinus under the name Clethrionomys gapperi caurinus (Bailey).

In spite of the treatment by Racey and Cowan ( op. cit. ) of occidentalis and caurinus as subspecies of C. gapperi , later authors arranged occidentalis as a member of the " californicus " group although they retained caurinus in the gapperi group. For example, Davis (The Recent Mammals of Idaho, The Caxton Printers, pp. 307-308, 1939) assigned C. caurinus to the gapperi group, although he regarded C. caurinus as a species (not a subspecies). He regarded also C. occidentalis as a species (not a subspecies) but assigned it to the californicus group. Dalquest (Univ. Kansas Publ., Mus. Nat. Hist., 2:344, April 9, 1948) considered occidentalis to be conspecific with Clethrionomys californicus and wrote ( op. cit. :101): "The californicus group, I feel, contains only the races of Clethrionomys californicus , while the gapperi group contains C. gapperi and its races, including caurinus , and possible other species." Dalquest gave no indication that he had examined any specimens of caurinus .

When Dalquest ( op. cit. :344) arranged occidentalis and californicus as subspecies of the same species, he used the name combination Clethrionomys californicus occidentalis because he ignored, or was unaware of, the page priority of occidentalis over californicus . We regard the anterior position of occidentalis as nomenclatural priority and therefore employ occidentalis rather than californicus as the specific name.

Differences between the gapperi group and the occidentalis group include: postpalatal bridge (complete in both groups) truncate posteriorly in the gapperi group and with a median, posteriorly directed, spine in the occidentalis group (this character is not evident in all specimens; some gapperi have a spine, and some occidentalis have the spine much reduced); dentition of the occidentalis group is heavier; enamel pattern of M3 and m1 in occidentalis more simplified—the number of salient and re-entrant angles tends to be reduced in adults of the occidentalis group.

An examination of specimens of caurinus (British Columbia: Mt. Seymour, 2 KU; Lund, Malaspina Inlet, 2 USBS; and Inverness, mouth Skeena River, 1 USBS), reveals that, in the presence of the median postpalatal spine and in the characters of the molars, caurinus agrees with the occidentalis group.

The red-backed mouse of the Olympic Peninsula was originally accorded specific rank. Currently it stands in the literature as a subspecies of the wide-spread species Clethrionomys gapperi because Dalquest (Univ. Kansas Publ. Mus. Nat. Hist., 2:343, April 9, 1948) used the name-combination Clethrionomys gapperi nivarius . Taylor and Shaw had earlier (Occas. Papers Charles R. Conner Mus., 2:23, 1929) indicated the same status by using the name Evotomys gapperi nivarius . Davis (The Recent Mammals of Idaho, The Caxton Printers, Caldwell, Idaho, p. 306, April 5, 1939), however, indicated that the affinities of nivarius were with the californicus [= occidentalis ] group, although he treated nivarius as a distinct species. We have examined two adult females (K. U. Nos. 10707 and 10708) of nivarius from Reflection Lake, 3800 ft., Jefferson County, Washington, and on the basis of their thick, instead of thin, pterygoid processes concur with Davis that the affinities of nivarius are with the named kinds of Clethrionomys now arranged as subspecies of Clethrionomys occidentalis , rather than with the kinds now arranged as subspecies of Clethrionomys gapperi . Although we are aware that Dalquest ( op. cit. :101-102) did not find actual intergradation between nivarius and Clethrionomys occidentalis occidentalis —a ten-mile gap separated their ranges—we prefer to use the name combination Clethrionomys occidentalis nivarius . In doing so we recognize that intergradation ultimately may be found between the two species C. occidentalis and C. gapperi ; in that event the name gapperi will apply as the name of the species because it has priority over occidentalis .

The following named kinds of Clethrionomys are considered to be subspecies of Clethrionomys occidentalis :

1890. Evotomys occidentalis Merriam, N. Amer. Fauna, 4:25, October 8, type from Aberdeen, Chehalis County, Washington.

1894. Evotomys pygmaeus Rhoads, Proc. Acad. Nat. Sci. Philadelphia, p. 284, October 23, type from mouth of Nisqually River, Pierce County, Washington.

1929. Evotomys gapperi occidentalis , Taylor and Shaw, Occas. Papers Charles R. Conner Mus., Washington State College, 2:23.

1948. Clethrionomys californicus occidentalis , Dalquest, Univ. Kansas Publ., Mus. Nat. Hist., 2:344, April 9.

The name rufescens , as applied by R. W. Smith (Amer. Midland Nat., 24:233, July, 1940) to the red-backed mouse of Nova Scotia, seems to be unavailable under the rules of the International Code of Zoological Nomenclature, since it is a homonym of Arvicola rufescens de Selys Longchamps, 1836, which in turn is a synonym of Clethrionomys glareolus glareolus Schreber, 1780 (Ellerman and Morrison-Scott, Checklist of Palaearctic and Indian Mammals, 1758 to 1946, p. 663, November 19, 1951).

When Swarth ( loc. cit. ) named the red-backed mouse of the mainland of southern Alaska as a new subspecies, he characterized it as "Size rather large. Differs from E. [= Clethrionomys ] wrangeli , nearest it geographically, in cranial characters and in much longer tail; from E. caurinus , the species to the southward in British Columbia, in larger size and longer tail." He remarked ( loc. cit. ): "I had supposed that the red-backed mouse occurring on the mainland coast of this region would prove to be E. wrangeli , but the latter appears to be purely an insular species. I have had no specimens of that race for comparison, but the Evotomys secured differ so widely from it in all the essential peculiarities of the species as given in the published descriptions that there seems little doubt of their belonging to a different species. Wrangeli has a short tail, less than twice as long as the hind foot—in adults of phaeus the tail is invariably more than twice the length of the foot, frequently more than a third of the entire length of the animal."

The external and cranial measurements of two subadults in the United States National Museum (No. 217413 from Quadra Lake and No. 217415 from Marten Arm, Boca de Quadra, taken in mid-February) and three old adults from Fort [= Port] Simpson, British Columbia (Nos. 90263-90264, 90272 USBS), are almost the same as those given by Swarth in the original description of Clethrionomys phaeus .

In cranial measurements, as well as in the structure of the palate and last upper molar, C. phaeus agrees with the gapperi group (to which it has been assigned by Davis, The Recent Mammals of Idaho, The Caxton Printers, p. 306, April 5, 1939, and by Orr, Jour. Mamm., 26:69, February 12, 1945) and differs from Clethrionomys occidentalis caurinus (which was assigned above to the occidentalis group, formerly the californicus group).

Since the measurements of specimens examined by us, as well as those recorded by Swarth ( op. cit. ), fall within the range of those of the species Clethrionomys gapperi , and since the differences between phaeus and C. g. saturatus are of the kind and degree that separate subspecies in C. gapperi we employ the name combination Clethrionomys gapperi phaeus (Swarth). C. g. saturatus , as understood by us, occurs to the southeast of C. g. phaeus in the Rocky Mountains of British Columbia, and in northeastern Washington, northern Idaho and northwestern Montana.

Specimens examined. —Total, 23, distributed as follows: Alaska: Chickamin River (Behm Canal), 15 (MVZ); Boca de Quadra, 3 (MVZ); Marten Arm, Boca de Quadra, 1 (USNM); Quadra Lake, 1 (USNM). British Columbia: Fort [= Port] Simpson, 3 (USBS).

When Bailey ( loc. cit. ) named the red-backed mouse from Wrangell Island, Alaska, he characterized it as "A large, dull-colored species entirely distinct from any known form," and remarked: "In no way does E. [= Clethrionomys ] wrangeli show a close relationship to any other American species. In size and relative proportions it comes closest to E. dawsoni , from which it differs widely in coloration and more widely in cranial characters. With the long-tailed species south and east of its range there is no need of comparison."

Swarth (Univ. California Publ. Zool., 24:173, June 17, 1922) reported that three specimens from Flood Glacier and 23 from Great Glacier, British Columbia, and four from Sergief Island, at the mouth of the Stikine River, Alaska, were: "All E. wrangeli , indistinguishable from specimens at hand from Wrangell Island." Swarth further reported that, although he found no intergradation between Clethrionomys wrangeli from Flood Glacier and the nearly adjacent Clethrionomys rutilus dawsoni , "the two species, however, resemble each other so closely in form, and in some pelages in color also, that wrangeli would seem to be a coastal offshoot of dawsoni ...."

Davis (The Recent Mammals of Idaho, The Caxton Printers, p. 306, April 5, 1939) and Orr (Jour. Mamm., 26:69, February 12, 1945) more recently have shown that Clethrionomys wrangeli is not a member of the rutilus group (to which C. dawsoni belongs) but is a member of the gapperi group.

Our comparisons of a series of eight topotypes of wrangeli (all in the Biological Surveys Collection) with several subspecies of Clethrionomys gapperi (including phaeus , saturatus , galei , brevicaudus , and others) reveal that the differences seen in wrangeli are of the kind and degree that serve to separate subspecies. The red-backed mouse from Wrangell Island, then, should stand as Clethrionomys gapperi wrangeli (Bailey).

Specimens examined. —Total, 31, distributed as follows: Alaska : Wrangell, Wrangell Island, 27 (19 MVZ., 8 USBS); Sergief Island at mouth of Stikine River, 4 (MVZ).

Clethrionomys gapperi solus , new subspecies

Type. —Male, adult, skin and skull, No. 74939, Biological Surveys Collection, United States National Museum; from Loring, Revillagigedo Island, Alaska; obtained on September 22, 1895, by C. P. Streator; original No. 4980.

Range. —Known only from two localities on Revillagigedo Island, Alaska.

Diagnosis. —A short-tailed, dark-colored member of the gapperi group. Dorsal stripe wide, between Chestnut and Bay (capitalized color terms after Ridgway: Color Standards and Color Nomenclature. Washington, D. C., 1912), with slight mixture of black-tipped hairs; sides and venter heavily washed with Ochraceous-Tawny. Skull flattened; rostrum proportionately short and wide; auditory bullae relatively uninflated.

Comparisons. —From topotypes of Clethrionomys gapperi wrangeli , C. g. solus differs as follows: dorsal stripe wider and slightly brighter; sides brighter; venter more heavily washed with Ochraceous-Tawny (heavy wash in all 13 C. g. solus examined; in C. g. wrangeli no wash in 11, slight wash in 16, and heavy wash in only one); nasals, alveolar extent of upper cheek-teeth and incisive foramina shorter; skull shallower when measured with tympanic bullae included; rostrum averages slightly broader.

From C. g. phaeus of the adjacent mainland, C. g. solus differs in: dorsal stripe slightly darker; ventral wash more prominent; tail shorter; skull smaller in all parts measured except that nasals are approximately the same length, auditory bullae notably smaller and teeth notably narrower.

Measurements. —External and cranial measurements of adults are shown in table 1.

Remarks. —Bailey (Proc. Biol. Soc. Washington, 11:120, May 13, 1897) referred 17 specimens from Loring to his newly named species, E. wrangeli [= Clethrionomys gapperi wrangeli ] but based his description on specimens from Wrangell Island. He pointed out ( loc. cit. ) that all of the specimens from Loring had the "bellies strongly washed with buffy-ochraceous, while more than half of those from Wrangell have whitish bellies."

Specimens examined. —Total, 13, all in the Biological Surveys Collection, U. S. National Museum, from the following localities: Alaska : Revillagigedo Island: Loring, 10; mouth of Fish Creek, Ketchikan, 3.

Clethrionomys gapperi stikinensis , new subspecies

Type. —Male, adult, skin and skull, No. 30735, Museum of Vertebrate Zoology, University of California; from Stikine River at Great Glacier, British Columbia; obtained on August 13, 1919, by J. Dixon; original number 7691.

Range. —Known only from the lower Stikine River Valley of British Columbia and the Cleveland Peninsula of Alaska.

Diagnosis. —A medium-sized, dark-colored member of the gapperi group. Dorsal stripe wide, near Auburn with mixture of black-tipped hairs; sides and venter washed with Ochraceous-Tawny. Skull small; cheek-teeth narrow; auditory bullae relatively uninflated.

Comparisons. —From topotypes of Clethrionomys gapperi wrangeli , C. g. stikinensis differs as follows: dorsal stripe slightly wider and brighter; sides slightly duller (lacking the olivaceous wash of C. g. wrangeli ); all cranial measurements taken averaging smaller except height of skull, which is approximately the same; alveolar length of upper tooth-row and length of incisive foramina notably shorter; auditory bullae less inflated; cheek-teeth much narrower.

From topotypes of C. g. phaeus , C. g. stikinensis differs as follows: dorsal stripe and sides darker; auditory bullae less inflated; cheek-teeth narrower; skull smaller in most measurements taken (see table 1).

From topotypes of C. g. solus , C. g. stikinensis differs as follows: dorsal stripe lighter (more tawny underwash); ventral wash of buffy much paler (especially noticeable around mouth and on throat); zygomatic and lambdoidal breadths greater; skull deeper; auditory bullae more inflated; cheek-teeth slightly heavier.

Measurements .—External and cranial measurements of adults are given in table 1.

Remarks .—Morphologically C. g. stikinensis shows greater resemblance to C. g. solus of Revillagigedo Island, than to the geographically adjacent subspecies C. g. wrangeli and C. g. phaeus . Possibly the original stock of C. g. solus was rafted to Revillagigedo Island from the Cleveland Peninsula.

Hanson (Trans. Wisconsin Acad. Sci., Arts, and Letters, 36:124, 1944) reported two pine mice from near Prairie du Sac, in Westpoint Township, Columbia County, Wisconsin, as Pitymys pinetorum scalopsoides but cast doubt upon their subspecific identity. He also reported pine mice from Blue Mounds, Dane County, Wisconsin. We have examined these specimens (Westpoint, Columbia County, 2—No. 544, skin only, UWDEZ, and No. 521, skin only, H. C. Hanson's private collection; Westpoint, Dane County, 1, No. 11620, UWZM; Vermont, Dane County, 2, Nos. 11674 and 11694, UWZM) and have compared them with topotypes of P. p. schmidti , and with specimens of P. p. nemoralis and P. p. scalopsoides . The specimens from Columbia and Dane counties differ from P. p. schmidti in the greater zygomatic breadth, and lesser height of skull. They differ from P. p. nemoralis of comparable age in shorter tooth-row and generally smaller skull. The interorbital region, however, is wider. In all of the features mentioned above, the specimens in question agree with Pitymys pinetorum scalopsoides , to which subspecies they are here referred.

Allen ( loc. cit. ) described this species on the basis of two specimens from Aztec, New Mexico, and three from La Plata, New Mexico. He characterized it as "Size large; pelage very full and soft; tail short; skull very narrow.

"Above grayish brown with a tinge of pale buff; fur blackish plumbeous beneath the surface, tipped with pale yellowish brown, and varied with longer, projecting, black-tipped hairs; below grayish white, the fur plumbeous beneath the surface and tipped with white, giving a whitish gray effect. Feet dusky; tail dusky brown above, dull white below."

Allen identified as this species "a large Arvicola from Estes Park, Colorado, which I have before been unable to allocate. I am unable to find that it differs in any particular from the specimens from New Mexico." He pointed out also ( op. cit. :73-74) that "The type and only positively identified specimen of Baird's Arvicola modesta [= Microtus pennsylvanicus modestus (Baird)] from Sawatche Pass, Colorado, is a very young specimen in poor condition. An examination of a series of adult and young examples from the type locality will be necessary in order to determine its relationships to A. alticolus [= Microtus longicaudus alticolus (Merriam)] and A. aztecus ."

Bailey, in his revision of the American voles of the genus Microtus (N. Amer. Fauna, 17:20), showed Arvicola modesta Baird to be a subspecies of Microtus pennsylvanicus but retained Microtus aztecus (Allen) as a distinct species. In describing M. aztecus he wrote "the size similar to M. pennsylvanicus , but with shorter tail and larger hindfoot; skull long; braincase narrow; interparietal long ..." and remarked that " Microtus aztecus belongs to the pennsylvanicus group. Externally it is not very different from modestus , but none of the specimens show any signs of intergradation; and the skull characters are so well marked that there seems no doubt of its full specific rank."

Subsequent to the publication of Allen's ( op. cit. ) account and Bailey's account ( op. cit. ), additional material was collected that helps to clarify the relationships of Microtus aztecus . A comparison of six adult topotypes of Microtus aztecus with a series of nine adults of M. p. modestus from 1 mi. S, 2 mi. E Eagle Nest, 8100 ft., Colfax County, New Mexico, with three adults from 1½ mi. E Manassa, Conejos County, Colorado, and with four adults from Saguache County, Colorado (all in KU), reveals that the supposed "well marked" external and cranial differences between the two forms are not nearly so evident as was indicated by Bailey.

The cranial differences that exist between these two forms (narrower nasals, slightly longer interparietal, slightly longer and narrower skull in aztecus ) are evident only as averages. Although geographically intermediate specimens are lacking, the morphological differences between the two kinds of animals are of the degree and kind that separate subspecies, rather than species. We therefore judge M. aztecus (Allen) to be only subspecifically distinct from M. pennsylvanicus modestus and employ the name Microtus pennsylvanicus aztecus .

Taylor and Shaw (Occas. Papers Charles R. Conner Mus., State College Washington, 2:24, December, 1929) list under Microtus nanus [= montanus ] canescens material from Calispell Peak, Washington. Probably the basis for this record is a specimen in the Biological Surveys collection (adult male, 236474) taken on May 9, 1921, by G. G. Cantwell, and labelled as Calispell Peak, 9 mi. W Locke, 3500 ft., Pend Oreille County. An examination (by Hall and Kelson) of the specimen discloses that it is of the species Microtus pennsylvanicus , and that it falls within the geographic range ascribed to the subspecies Microtus pennsylvanicus funebris by Dalquest (Univ. Kansas Publ., Mus. Nat. Hist., 2:346, April 9, 1948).

When Murie (Jour. Mamm., 11:75, February 11, 1930) named the meadow mouse from Amak Island, Alaska, as amakensis , he arranged it as a separate species. One of us (Hall) and K. R. Kelson examined the type and topotypes of amakensis in the Biological Surveys collection in the U. S. National Museum and compared them with series of Microtus oeconomus operarius , M. o. sitkensis , M. o. elymocetes , M. o. yakutatensis , and M. o. kadiacensis . Among the specimens examined of the latter subspecies were 17 from Izambek Bay, Kodiak Peninsula, on the mainland opposite Amak Island, the type locality of amakensis . The characters given by Murie ( op. cit. ) serve to separate amakensis from closely related neighboring kinds of meadow mice, but are of the degree and kind that, in this group of meadow mice, separate subspecies rather than species. Although actual intergrades are lacking, the animals from Amak Island are considered to be only subspecifically distinct and to belong to the oeconomus complex. The name Microtus oeconomus amakensis is applied to them.

Dalquest (Univ. Kansas Publ., Mus. Nat. Hist., 2:353, April 9, 1948) assigned all the meadow mice of the species Microtus longicaudus from approximately the eastern half of Washington State to Microtus longicaudus halli Hayman and Holt and, in doing so, excluded the subspecies Microtus longicaudus mordax from that state. This assignment of specimens in Washington had the effect of separating the geographic range of M. l. mordax into two parts. One part was in south-central British Columbia and the other part was mainly in the Rocky Mountain region of the United States. Hall and Kelson examined specimens in the Biological Surveys collection in the U. S. National Museum in an attempt to determine more precisely the ranges of the subspecies in southern Canada, Washington, and Idaho.

Microtus longicaudus angustus [= M. l. halli ] was described by one of us (Hall, Univ. California Publ. Zool., 37:13, April 10, 1931) as differing from mordax in narrower braincase, higher skull near the anterior end of the frontals, darker coloration, and seemingly smaller size. After examining the material in the U. S. National Museum no reason is seen at the present time to amend this characterization, except to add that some specimens of M. l. mordax are as dark as seasonably comparable specimens of M. l. halli .

Examination of specimens of Microtus longicaudus from Washington east of the Cascade Range (those from the Blue Mountain area excepted) discloses that the skulls do not differ essentially from those of topotypes of M. l. mordax , but do differ, as outlined above, from near-topotypes of M. l. halli . There is considerable variation in color among the Washington-taken specimens of Microtus longicaudus . Animals from the eastern flanks of the Cascades average darker than those taken, north of the Snake River, still farther east in Washington. Possibly Dalquest ( op. cit. ) relied mainly upon this darker color in assigning the specimens from eastern Washington to M. l. halli . Relying principally upon cranial characters, we conclude that most of the specimens are better referred to M. l. mordax and that M. l. halli is restricted, in Washington, to the Blue Mountains.

Specimens examined of Microtus longicaudus mordax. —Total, 74, all in the Biological Surveys Collection, distributed as follows: Washington: Okanogan County : mouth of Holmar Creek, W Fork Paysaten River, 4700 ft., 1; Conconully, 3; Twisp, 1; Omak Lake, 1200 ft., 3. Stevens County : 5 mi. N Colville, 1. Pend Oreille County : 9 mi. N Metalina, 2600 ft., 1; Sullivan Lake, 3000 ft., 3. Chelan County : Sethekin, 1079 ft., 3; head of Lake Chelan, 900 ft., 12; Hart Lake, Railroad Creek, 3900 ft., 1; Entiat, 20 mi from mouth of Entiat River, 1680 ft., 13; Wenatchee, 4. Douglas County : Waterville, 1. Jefferson County : Cleveland, 2. Kittitas County : 2 mi. S Blewett Pass, 3000 ft., 6: Ellensburg, 1500 ft., 4. Whitman County : Colfax, 2. Yakima County : McAllister Meadows, Tieton River, 3000 ft., 3; Gotchen Cr., 5500 ft., near Sava Spring, Mt. Adams, 2. Klickitat County : 8 mi. S Glenwood, base Mt. Adams, 2. Asotin County : Anatone, 3300 ft., 4; Bly, 1000 ft., 2.

Rausch (Jour. Washington Acad. Sci., 40:135, April 21, 1950) proposed the name Microtus miurus paneaki , with type locality at Tolugak Lake (lat. 68° 24′ N, long. 152° 10′ W), Brooks Range, Alaska, for a meadow mouse of the subgenus Stenocranius . This place is only approximately forty miles east and north of the type locality of the earlier named Microtus muriei , also a member of the subgenus Stenocranius . Large series of specimens of this subgenus, from the Arctic Slope of Alaska, are in the Museum of Natural History of the University of Kansas. Study of these indicates that the differences, which Rausch ( op. cit. :136) described as distinguishing his M. m. paneaki from M. muriei , result from differences in age of the specimens, and possibly in part from differences in seasonal condition of pelage. For example, Rausch thought that M. m. paneaki was larger than M. muriei but our specimens reveal that such is not the case. The measurements given below of the type specimen of M. muriei (after Nelson, original description) and measurements (in parentheses) of an immature female (43807 K. U.) of Microtus miurus muriei from Chandler Lake, 68° 12′, 152° 45′, 2900 ft., Alaska, show close correspondence in size. Total length, 119 (122); tail vertebrae, 24 (24); hind foot, 20 (20); condylobasal length, 24.3 (24.5); zygomatic breadth, 10.7 (11.0); greatest width of braincase, 9.0 (9.0); length of nasals, 6.5 (6.0); basal width of rostrum, 4.0 (4.3). In the light of all of the evidence now available, it seems best to treat Microtus miurus paneaki Rausch as a synonym of Microtus muriei Nelson.

Quay (Jour. Mamm., 32:95, February 15, 1951) identified fifty-eight specimens from the Seward Peninsula of Alaska as Microtus miurus oreas Osgood. Through the courtesy of Dr. Charles P. Lyman, fifteen of Quay's specimens in the Museum of Comparative Zoology at Harvard College have been examined by one of us (Hall). These specimens are as follows: Lava Lake (43378, 43379, 43381, 43382, 43386, 43467 and 43478); Mt. Boyan (43384, 43385, 43463 and 43477); Anvil Hill [= Peak], Cooper Gulch (43377, 43464 and 43473); ——? Lake, 43383. Although we are not prepared to say that these specimens are M. m. muriei , they seem to resemble M. m. muriei as closely as they do any other named form and we here refer them to that subspecies.

The facts are that a critical taxonomic study of the American specimens of the subgenus Stenocranius is required in order to ascertain the geographic variation. One of us (Hall) has examined the holotypes of the kinds named from Alaska, and the material listed by R. Baker (Univ. Kansas Publ. Mus. Nat. Hist., 5:109) of the two kinds named from Canada. The degree and nature of the variation shown by these specimens lead us to the conclusion that all are of a single species. If the American mouse is specifically distinct from any of the previously named Asiatic species—at this writing we lack material to decide this question—the named kinds from the mainland of the New World may stand as follows:

*** END OF THE PROJECT GUTENBERG EBOOK COMMENTS ON THE TAXONOMY AND GEOGRAPHIC DISTRIBUTION OF NORTH AMERICAN MICROTINES ***

Updated editions will replace the previous one—the old editions will be renamed.

Creating the works from print editions not protected by U.S. copyright law means that no one owns a United States copyright in these works, so the Foundation (and you!) can copy and distribute it in the United States without permission and without paying copyright royalties. Special rules, set forth in the General Terms of Use part of this license, apply to copying and distributing Project Gutenberg™ electronic works to protect the PROJECT GUTENBERG™ concept and trademark. Project Gutenberg is a registered trademark, and may not be used if you charge for an eBook, except by following the terms of the trademark license, including paying royalties for use of the Project Gutenberg trademark. If you do not charge anything for copies of this eBook, complying with the trademark license is very easy. You may use this eBook for nearly any purpose such as creation of derivative works, reports, performances and research. Project Gutenberg eBooks may be modified and printed and given away—you may do practically ANYTHING in the United States with eBooks not protected by U.S. copyright law. Redistribution is subject to the trademark license, especially commercial redistribution.

START: FULL LICENSE

PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK

To protect the Project Gutenberg™ mission of promoting the free distribution of electronic works, by using or distributing this work (or any other work associated in any way with the phrase “Project Gutenberg”), you agree to comply with all the terms of the Full Project Gutenberg™ License available with this file or online at www.gutenberg.org/license.

Section 1. General Terms of Use and Redistributing Project Gutenberg™ electronic works

1.A. By reading or using any part of this Project Gutenberg™ electronic work, you indicate that you have read, understand, agree to and accept all the terms of this license and intellectual property (trademark/copyright) agreement. If you do not agree to abide by all the terms of this agreement, you must cease using and return or destroy all copies of Project Gutenberg™ electronic works in your possession. If you paid a fee for obtaining a copy of or access to a Project Gutenberg™ electronic work and you do not agree to be bound by the terms of this agreement, you may obtain a refund from the person or entity to whom you paid the fee as set forth in paragraph 1.E.8.

1.B. “Project Gutenberg” is a registered trademark. It may only be used on or associated in any way with an electronic work by people who agree to be bound by the terms of this agreement. There are a few things that you can do with most Project Gutenberg™ electronic works even without complying with the full terms of this agreement. See paragraph 1.C below. There are a lot of things you can do with Project Gutenberg™ electronic works if you follow the terms of this agreement and help preserve free future access to Project Gutenberg™ electronic works. See paragraph 1.E below.

1.C. The Project Gutenberg Literary Archive Foundation (“the Foundation” or PGLAF), owns a compilation copyright in the collection of Project Gutenberg™ electronic works. Nearly all the individual works in the collection are in the public domain in the United States. If an individual work is unprotected by copyright law in the United States and you are located in the United States, we do not claim a right to prevent you from copying, distributing, performing, displaying or creating derivative works based on the work as long as all references to Project Gutenberg are removed. Of course, we hope that you will support the Project Gutenberg™ mission of promoting free access to electronic works by freely sharing Project Gutenberg™ works in compliance with the terms of this agreement for keeping the Project Gutenberg™ name associated with the work. You can easily comply with the terms of this agreement by keeping this work in the same format with its attached full Project Gutenberg™ License when you share it without charge with others.

1.D. The copyright laws of the place where you are located also govern what you can do with this work. Copyright laws in most countries are in a constant state of change. If you are outside the United States, check the laws of your country in addition to the terms of this agreement before downloading, copying, displaying, performing, distributing or creating derivative works based on this work or any other Project Gutenberg™ work. The Foundation makes no representations concerning the copyright status of any work in any country other than the United States.

1.E. Unless you have removed all references to Project Gutenberg:

1.E.1. The following sentence, with active links to, or other immediate access to, the full Project Gutenberg™ License must appear prominently whenever any copy of a Project Gutenberg™ work (any work on which the phrase “Project Gutenberg” appears, or with which the phrase “Project Gutenberg” is associated) is accessed, displayed, performed, viewed, copied or distributed:

This eBook is for the use of anyone anywhere in the United States and most other parts of the world at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at www.gutenberg.org . If you are not located in the United States, you will have to check the laws of the country where you are located before using this eBook.

1.E.2. If an individual Project Gutenberg™ electronic work is derived from texts not protected by U.S. copyright law (does not contain a notice indicating that it is posted with permission of the copyright holder), the work can be copied and distributed to anyone in the United States without paying any fees or charges. If you are redistributing or providing access to a work with the phrase “Project Gutenberg” associated with or appearing on the work, you must comply either with the requirements of paragraphs 1.E.1 through 1.E.7 or obtain permission for the use of the work and the Project Gutenberg™ trademark as set forth in paragraphs 1.E.8 or 1.E.9.

1.E.3. If an individual Project Gutenberg™ electronic work is posted with the permission of the copyright holder, your use and distribution must comply with both paragraphs 1.E.1 through 1.E.7 and any additional terms imposed by the copyright holder. Additional terms will be linked to the Project Gutenberg™ License for all works posted with the permission of the copyright holder found at the beginning of this work.

1.E.4. Do not unlink or detach or remove the full Project Gutenberg™ License terms from this work, or any files containing a part of this work or any other work associated with Project Gutenberg™.

1.E.5. Do not copy, display, perform, distribute or redistribute this electronic work, or any part of this electronic work, without prominently displaying the sentence set forth in paragraph 1.E.1 with active links or immediate access to the full terms of the Project Gutenberg™ License.

1.E.6. You may convert to and distribute this work in any binary, compressed, marked up, nonproprietary or proprietary form, including any word processing or hypertext form. However, if you provide access to or distribute copies of a Project Gutenberg™ work in a format other than “Plain Vanilla ASCII” or other format used in the official version posted on the official Project Gutenberg™ website (www.gutenberg.org), you must, at no additional cost, fee or expense to the user, provide a copy, a means of exporting a copy, or a means of obtaining a copy upon request, of the work in its original “Plain Vanilla ASCII” or other form. Any alternate format must include the full Project Gutenberg™ License as specified in paragraph 1.E.1.

1.E.7. Do not charge a fee for access to, viewing, displaying, performing, copying or distributing any Project Gutenberg™ works unless you comply with paragraph 1.E.8 or 1.E.9.

1.E.8. You may charge a reasonable fee for copies of or providing access to or distributing Project Gutenberg™ electronic works provided that:

• You pay a royalty fee of 20% of the gross profits you derive from the use of Project Gutenberg™ works calculated using the method you already use to calculate your applicable taxes. The fee is owed to the owner of the Project Gutenberg™ trademark, but he has agreed to donate royalties under this paragraph to the Project Gutenberg Literary Archive Foundation. Royalty payments must be paid within 60 days following each date on which you prepare (or are legally required to prepare) your periodic tax returns. Royalty payments should be clearly marked as such and sent to the Project Gutenberg Literary Archive Foundation at the address specified in Section 4, “Information about donations to the Project Gutenberg Literary Archive Foundation.”
• You provide a full refund of any money paid by a user who notifies you in writing (or by e-mail) within 30 days of receipt that s/he does not agree to the terms of the full Project Gutenberg™ License. You must require such a user to return or destroy all copies of the works possessed in a physical medium and discontinue all use of and all access to other copies of Project Gutenberg™ works.
• You provide, in accordance with paragraph 1.F.3, a full refund of any money paid for a work or a replacement copy, if a defect in the electronic work is discovered and reported to you within 90 days of receipt of the work.
• You comply with all other terms of this agreement for free distribution of Project Gutenberg™ works.

1.E.9. If you wish to charge a fee or distribute a Project Gutenberg™ electronic work or group of works on different terms than are set forth in this agreement, you must obtain permission in writing from the Project Gutenberg Literary Archive Foundation, the manager of the Project Gutenberg™ trademark. Contact the Foundation as set forth in Section 3 below.

1.F.

1.F.1. Project Gutenberg volunteers and employees expend considerable effort to identify, do copyright research on, transcribe and proofread works not protected by U.S. copyright law in creating the Project Gutenberg™ collection. Despite these efforts, Project Gutenberg™ electronic works, and the medium on which they may be stored, may contain “Defects,” such as, but not limited to, incomplete, inaccurate or corrupt data, transcription errors, a copyright or other intellectual property infringement, a defective or damaged disk or other medium, a computer virus, or computer codes that damage or cannot be read by your equipment.

1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the “Right of Replacement or Refund” described in paragraph 1.F.3, the Project Gutenberg Literary Archive Foundation, the owner of the Project Gutenberg™ trademark, and any other party distributing a Project Gutenberg™ electronic work under this agreement, disclaim all liability to you for damages, costs and expenses, including legal fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE PROVIDED IN PARAGRAPH 1.F.3. YOU AGREE THAT THE FOUNDATION, THE TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH DAMAGE.

1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a defect in this electronic work within 90 days of receiving it, you can receive a refund of the money (if any) you paid for it by sending a written explanation to the person you received the work from. If you received the work on a physical medium, you must return the medium with your written explanation. The person or entity that provided you with the defective work may elect to provide a replacement copy in lieu of a refund. If you received the work electronically, the person or entity providing it to you may choose to give you a second opportunity to receive the work electronically in lieu of a refund. If the second copy is also defective, you may demand a refund in writing without further opportunities to fix the problem.

1.F.4. Except for the limited right of replacement or refund set forth in paragraph 1.F.3, this work is provided to you ‘AS-IS’, WITH NO OTHER WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PURPOSE.

1.F.5. Some states do not allow disclaimers of certain implied warranties or the exclusion or limitation of certain types of damages. If any disclaimer or limitation set forth in this agreement violates the law of the state applicable to this agreement, the agreement shall be interpreted to make the maximum disclaimer or limitation permitted by the applicable state law. The invalidity or unenforceability of any provision of this agreement shall not void the remaining provisions.

1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the trademark owner, any agent or employee of the Foundation, anyone providing copies of Project Gutenberg™ electronic works in accordance with this agreement, and any volunteers associated with the production, promotion and distribution of Project Gutenberg™ electronic works, harmless from all liability, costs and expenses, including legal fees, that arise directly or indirectly from any of the following which you do or cause to occur: (a) distribution of this or any Project Gutenberg™ work, (b) alteration, modification, or additions or deletions to any Project Gutenberg™ work, and (c) any Defect you cause.

Section 2. Information about the Mission of Project Gutenberg™

Project Gutenberg™ is synonymous with the free distribution of electronic works in formats readable by the widest variety of computers including obsolete, old, middle-aged and new computers. It exists because of the efforts of hundreds of volunteers and donations from people in all walks of life.

Volunteers and financial support to provide volunteers with the assistance they need are critical to reaching Project Gutenberg™’s goals and ensuring that the Project Gutenberg™ collection will remain freely available for generations to come. In 2001, the Project Gutenberg Literary Archive Foundation was created to provide a secure and permanent future for Project Gutenberg™ and future generations. To learn more about the Project Gutenberg Literary Archive Foundation and how your efforts and donations can help, see Sections 3 and 4 and the Foundation information page at www.gutenberg.org.

Section 3. Information about the Project Gutenberg Literary Archive Foundation

The Project Gutenberg Literary Archive Foundation is a non-profit 501(c)(3) educational corporation organized under the laws of the state of Mississippi and granted tax exempt status by the Internal Revenue Service. The Foundation’s EIN or federal tax identification number is 64-6221541. Contributions to the Project Gutenberg Literary Archive Foundation are tax deductible to the full extent permitted by U.S. federal laws and your state’s laws.

The Foundation’s business office is located at 809 North 1500 West, Salt Lake City, UT 84116, (801) 596-1887. Email contact links and up to date contact information can be found at the Foundation’s website and official page at www.gutenberg.org/contact

Section 4. Information about Donations to the Project Gutenberg Literary Archive Foundation

Project Gutenberg™ depends upon and cannot survive without widespread public support and donations to carry out its mission of increasing the number of public domain and licensed works that can be freely distributed in machine-readable form accessible by the widest array of equipment including outdated equipment. Many small donations ($1 to $5,000) are particularly important to maintaining tax exempt status with the IRS.

The Foundation is committed to complying with the laws regulating charities and charitable donations in all 50 states of the United States. Compliance requirements are not uniform and it takes a considerable effort, much paperwork and many fees to meet and keep up with these requirements. We do not solicit donations in locations where we have not received written confirmation of compliance. To SEND DONATIONS or determine the status of compliance for any particular state visit www.gutenberg.org/donate .

While we cannot and do not solicit contributions from states where we have not met the solicitation requirements, we know of no prohibition against accepting unsolicited donations from donors in such states who approach us with offers to donate.

International donations are gratefully accepted, but we cannot make any statements concerning tax treatment of donations received from outside the United States. U.S. laws alone swamp our small staff.

Please check the Project Gutenberg web pages for current donation methods and addresses. Donations are accepted in a number of other ways including checks, online payments and credit card donations. To donate, please visit: www.gutenberg.org/donate.

Section 5. General Information About Project Gutenberg™ electronic works

Professor Michael S. Hart was the originator of the Project Gutenberg™ concept of a library of electronic works that could be freely shared with anyone. For forty years, he produced and distributed Project Gutenberg™ eBooks with only a loose network of volunteer support.

Project Gutenberg™ eBooks are often created from several printed editions, all of which are confirmed as not protected by copyright in the U.S. unless a copyright notice is included. Thus, we do not necessarily keep eBooks in compliance with any particular paper edition.

Most people start at our website which has the main PG search facility: www.gutenberg.org .

This website includes information about Project Gutenberg™, including how to make donations to the Project Gutenberg Literary Archive Foundation, how to help produce our new eBooks, and how to subscribe to our email newsletter to hear about new eBooks.

Number of individuals averaged of each sex or specimen measured	Total length	Tail	Hind foot	Condy- lobasilar length	Zygomatic breadth	Lambdoidal breadth	Length of nasals	Alveolar length of upper tooth- row	Breadth of rostrum	Length of incisive foramina	Height of skull
Clethrionomys gapperi solus , Loring
♂type	133	33	20	22.3	12.5	10.9	6.8	5.1	3.4	5.3	9.0
♂ 5 av.	131	34	20	22	12.7	10.8	6.8	5.3	3.5	5.1	9.1
min.	128	33	19	21.8	12.5	10.5	6.7	5.1	3.3	5.0	8.9
max.	133	36	20	22.3	13.0	11.2	7.1	5.5	3.6	5.3	9.5
♀ 5 av.	128	34	19	21.3	12.5	10.5	6.5	5.4	3.5	4.9	9.2
min.	124	31	19	20.9	12.3	10.3	6.0	5.2	3.3	4.8	8.9
max.	140	36	20	21.7	12.7	10.7	7.0	5.6	3.6	5.0	9.5
Clethrionomys gapperi stikinensis , Stikine River at Great Glacier
♂ type	145	39	20	23.2	13.9	11.4	7.3	5.0	3.1	5.5	9.5
♂ 4 av.	136	5	20	22.2	13.0	11.1	6.8	5.2	3.4	5.2	9.4
min.	132	33	19	21.5	12.3	10.7	6.5	5.0	3.1	5.1	9.1
max.	145	39	20	23.2	13.9	11.4	7.3	5.6	3.5	5.5	9.7
♀ 7 av.	134	33	19	21.8	12.7 ^{6 *}	10.9	7.0	5.4	3.4	5.1	9.5
min.	125	30	19	21.5	12.5	10.5	6.7	5.3	3.2	5.0	9.2
max.	147	35	20	22.2	12.9	11.3	7.1	5.6	3.7	5.3	9.8
Clethrionomys gapperi wrangeli , Wrangell
♂9 av.	139	36	19	23.4 ⁸	13.3	11.4 ⁸	7.3	5.6	3.6	5.6	9.6 ⁸
min.	130	31	18	22.9	13.0	10.9	7.1	5.5	3.3	5.4	9.2
max.	151	43	20	23.9	13.7	11.8	7.6	5.8	4.0	5.8	10.1
♀ 16 av.	134	34	18 ¹⁵	23.2	13.3	11.2 ¹³	7.3	5.8	3.5	5.5	9.4
min.	123	28	17	22.4	12.6	10.7	6.9	5.5	3.2	5.2	9.0
max.	156	45	20	24.1	14.1	11.8	8.0	6.1	3.7	5.9	9.7
Clethrionomys gapperi phaeus , Chickamin River
♂ 5 av.	148	47	20	23.0 ⁴	13.7 ⁴	11.3 ⁴	7.5 ⁴	5.3 ⁴	3.5 ⁴	5.3 ⁴	9.7 ³
min.	138	38	20	22.3	13.0	11.1	7.1	5.3	3.4	4.9	9.3
max.	159	51	21	23.8	14.6	11.8	7.7	5.6	3.8	5.6	10.0
♀ 4 av.	153	49	20	23.1 ³	13.4	11.2 ³	7.6 ³	5.2	3.7	5.3	9.6 ³
min.	140	44	20	22.4	12.8	10.8	7.3	5.0	3.4	5.1	9.2
max.	164	56	20	24.2	13.6	11.4	7.7	5.3	3.9	5.5	9.8

The Project Gutenberg eBook of Comments on the Taxonomy and Geographic Distribution of North American Microtines

Comments on
the Taxonomy and Geographic Distribution
of North American Microtines

BY

E. RAYMOND HALL AND E. LENDELL COCKRUM

University of Kansas Publications
Museum of Natural History
Volume 5, No. 23, pp. 293-312
November 17, 1952

University of Kansas
LAWRENCE
1952

University of Kansas Publications, Museum of Natural History

Editors: E. Raymond Hall, Chairman, A. Byron Leonard,
Edward H. Taylor, Robert W. Wilson

Volume 5, No. 23, pp. 293-312
November 17, 1952

University of Kansas
Lawrence, Kansas

PRINTED BY
FERD VOILAND, JR., STATE PRINTER
TOPEKA, KANSAS 1952

THE FULL PROJECT GUTENBERG LICENSE

The Project Gutenberg eBook of Comments on the Taxonomy and Geographic Distribution of North American Microtines

Comments on the Taxonomy and Geographic Distribution of North American Microtines

BY

E. RAYMOND HALL AND E. LENDELL COCKRUM

University of Kansas Publications Museum of Natural History Volume 5, No. 23, pp. 293-312 November 17, 1952

University of Kansas LAWRENCE 1952

University of Kansas Publications, Museum of Natural History

Editors: E. Raymond Hall, Chairman, A. Byron Leonard, Edward H. Taylor, Robert W. Wilson

Volume 5, No. 23, pp. 293-312 November 17, 1952

University of Kansas Lawrence, Kansas

PRINTED BY FERD VOILAND, JR., STATE PRINTER TOPEKA, KANSAS 1952

THE FULL PROJECT GUTENBERG LICENSE

Comments on
the Taxonomy and Geographic Distribution
of North American Microtines

University of Kansas Publications
Museum of Natural History
Volume 5, No. 23, pp. 293-312
November 17, 1952

University of Kansas
LAWRENCE
1952

Editors: E. Raymond Hall, Chairman, A. Byron Leonard,
Edward H. Taylor, Robert W. Wilson

Volume 5, No. 23, pp. 293-312
November 17, 1952

University of Kansas
Lawrence, Kansas

PRINTED BY
FERD VOILAND, JR., STATE PRINTER
TOPEKA, KANSAS 1952