An adult female, no. 426a, Iowa State College, from Barnum, in the brown winter coat, agrees withprimulinaexcept that the orbitonasal length of the skull is more as inspadixand the presence of some light color on the lower part of the hind legs suggestsspadix. The skull only, no. 440a, Iowa State College, labeled merely Webster County, Iowa, is almost a duplicate of no. 426a. A subadult male, no. 427a, Iowa State College, from Moorland, Iowa, only about six miles southeast of Barnum, likewise is indistinguishable fromprimulinaexcept for having a white winter coat and in being relatively broad in the mastoidal region. Nevertheless, both of these animals are here referred tospadixbecause the average of specimens from this general area is nearer that ofspadix. No. 497a, Iowa State College, an adult female in white winter pelage, from Ames, approachesprimulinain the narrow rostrum and smaller teeth but otherwise approaches or even agrees withspadix.
Two adult males, without external measurements, from Pilot Mound, Iowa, have skulls quite like males oflongicaudafrom Alberta. The only approach noted to eastern forms is the restricted color of the underparts on no. 2856, Coe College, which has a brown winter coat. The color of the underparts is not extended so far out on the feet as inlongicauda. Also the tympanic bullae of this specimen are a trifle narrower. The other male, no. 2652, is in the white winter coat. The one female from the same place, no. 2660, Coe College, in brown winter pelage, has a skull notably unlike that oflongicaudaorspadix; the skull is narrower and practically indistinguishable from that of the largest female skull ofprimulinaavailable from Lawrence, Kansas, save that the tooth-row is much longer. The color pattern also agrees with that ofprimulinaornoveboracensisin that the color of the underparts extends only as far as the knee on the hind legs and is narrow on the belly. Nevertheless, another adult female, no. 120a from Amaqua Township, some 6 miles southwest of Pilot Mound, is in all respects typical ofspadix. This is the more remarkable because another comparable specimen from less than 20 miles to the southwest in Worth Township is equally typical ofprimulina.
Two young females from Chester, Iowa, nos. 2656 and 2874/2873, Coe College, have skulls larger than those of corresponding age ofprimulinaornoveboracensis. The color is as in spadix. The color pattern of the underparts also is as inspadixorlongicaudaexcept that the width of the area of light color on the belly is restricted somewhat although not so much as innoveboracensisorprimulina. Of four males from the same place, also in the collection of Coe College, no. A2874 is a white skin only and does not provide diagnostic characters. The three other males, each in summer pelage, are marked and colored as are the two females from the same place except that male no. 2861 has the color of the underparts so much attenuated on the hind legs that it barely, uninterruptedly, extends to the feet. No. 2658 is young, or perhaps barely subadult. The skull is large and referable tospadix. The two adults, nos. 2861 and 2657, differ cranially from typical (Elk River, Minn.)spadixonly in being slightly narrower across the mastoids and in having the bullae a little narrower. In these departures they show some approach toprimulinaand tonoveboracensis. Another male, subadult, no. 2867, Coe College, from Decorah, which has acquired half of the white winter coat, agrees with the males from Chester except that the preorbital part of the skull is shortened much as in some specimens ofprimulina.
From Lansing, in extreme northeastern Iowa, a large subadult male, no. 2864, Coe College, of 453 mm. in total length and half through with acquiring the white winter coat, agrees with the males previously described from Chester except in having the palate narrower as innoveboracensis. The adult female available from Lansing, no. 2863/2862, Coe College, in white winter pelage except for the top of the head, although a large skin, has a skull smaller than that of anyspadixorlongicaudaand of about the same size as that of no. 3838, Univ. Kansas Mus. Nat. Hist., ofprimulina, from Lawrence, Kansas, except that the skull of no. 2863/2862 is much narrower across the mastoids. This specimen, then, shows approach tonoveboracensisin narrowness of the mastoidal region, toprimulinain other respects and tospadix.
Many of these instructive specimens from Iowa, made available to the present writer by Mr. W. F. Kubichek, were brought together at the Coe College Museum by the late B. H. Bailey. Most of them were obtained from trappers who did not supply the conventional external measurements taken in the flesh. Even though these are lacking, the specimens clearly show that actual intergradation occurs where the ranges ofM. f. longicauda,spadix,noveboracensisandprimulinameet.
The dark color of the upper parts, restriction of the color of the underparts on the ankles with the result that the color reaches the toes in interrupted fashion, and large skull, of no. 18912 of the Museum of the University of South Dakota, from Roberts County, South Dakota, clearly place this specimen withspadix, rather than withlongicauda. Likewise, male, subadult, no. 11376, Univ. South Dakota, from Clay County, South Dakota, is referable tospadix. Although without external measurements, the specimen obviously is large. The patch of summer pelage on its head and neck is darker than the summer pelage oflongicauda, and the orbitonasal length is greater than the length of the tympanic bullae; all these features are characters ofspadix. The adult male from Fort Sisseton, South Dakota, no. 188407, United States National Museum, figured by Merriam (1896, p. 20, figs. 7-9), is almost exactly intermediate betweenlongicaudaandspadix, although here referred to the latter.
Five specimens, nos. 147375, 147432, 147762, 148720 and 148721, U. S. Nat. Mus., including 3 skulls only from Beemer, Cuming County, Nebraska, are intergrades betweenM. f. longicauda,M. f. primulinaandM. f. spadix. One skin is in white winter pelage and the other, a female, is in summer pelage which in coloration and color pattern agrees with that ofspadix. External measurements of the male agree with those oflongicauda. Measurements of the female agree with those ofspadixexcept that the tail is shorter as inprimulina. The skulls are as long as inlongicaudabut are more slender than in eitherlongicaudaorspadixalthough nearer the latter in this respect. In dorsal aspect, the skulls especially posteriorly to the orbital region, resembleprimulina. All points considered, the animals seem best referred tospadix.
Although the degree of development of certain morphological features has been settled upon as indicative of the racespadix, some doubt remains as to where the western boundary of its range should be shown. This results from the fact that color has been taken into account as one diagnostic feature and this feature is lacking in the white winter specimens which, from the following places, are all that are available: Kittson County, Minnesota; Moorhead, Minnesota; Casselton and Valley City in North Dakota; Armour, South Dakota and Clay County, South Dakota. In summary, more specimens in the summer coat will be required to establish definitely the boundary between the ranges oflongicaudaandspadix.
Surber (1932:49) has referred to additional specimens of this weasel in the University of Minnesota Museum as from Winona, Hennepin and Isanti counties of that state.
At Elk River, Minnesota, B. Bailey (1929:156) found this species to be about half as abundant asMustela cicognaniiand that it is "more often found in the open timber and about the dry ridges and fields." Of seventeen adult or subadult skulls of this race from Minnesota, ten have obvious marks of infestation of the frontal sinuses. In no skull, however, has the infestation resulted in so much malformation, as occurs innoveboracensis.
Specimens examined.—Total number, 76, arranged alphabetically by states and from north to south by counties in each state.Iowa.Lyon County: Granite, 1[65].Howard County: Chester, 6[12].Winneshiek County: Decorah, 1[12]; 8 mi. NE Ossian, 1[76].Allamakee County: Lansing, 2[12].Clay County: Island, 1[76]; Webb, 1[2].Palo Alto County: Ruthven, 1[76]; no locality more definite than county, 1[76].Calhoun County: Manson, 1[65].Webster County: Barnum, 1[65]; Moorland, 1[65]; no locality more definite than county, 1[65].Boone County: Pilot Mound, 3[12]; Amaqua Township, Sec. 19, 1[65].Story County: Ames, 1[65].Minnesota.Kittson County, 1[2].Roseau County: 2-1/2 mi. SW Roseau, Jadis Township, 1[14].Itasca County: T. 61N, R. 26W, 1[102].Clay County: Moorhead, 2[9].Atkin County: Atkin, 1[50].Otter Tail County: Lake Lizzie, 1[9]; Parkers Prairie, 1[57].Grant County: 3 mi. NW Barrett, 1[76].Benton(now Mille Lacs?)County: Princeton, 1[91].Sherburne County: Elk River, 14 (6[59], 4[14], 3[91], 1[74]).Hennepin County: Fort Snelling, 6 (5[2], 1[91]).Carver? County: Chaska, 1[60].Lac qui Parle County: Madison, 5 (3[91], 2[1]); no locality more definite than county, 2 (1[68], 1[75]).Yellow Medicine County: Wood Lake, 1[2].Blue Earth County: Rapidan, 1[64].Countyin question: Moore Lake, 1[91].Nebraska.Cuming County: Beemer, 5[91].North Dakota.Cass County: Fargo, 1[91]; Casselton, 1[91].Dickey County: Oakes, 1[91].South Dakota.Roberts County, 1[102].Marshall County: Fort Sisseton, 1[91].Douglas County: Armour, 1[14].Clay County, 1[102].
Specimens examined.—Total number, 76, arranged alphabetically by states and from north to south by counties in each state.
Iowa.Lyon County: Granite, 1[65].Howard County: Chester, 6[12].Winneshiek County: Decorah, 1[12]; 8 mi. NE Ossian, 1[76].Allamakee County: Lansing, 2[12].Clay County: Island, 1[76]; Webb, 1[2].Palo Alto County: Ruthven, 1[76]; no locality more definite than county, 1[76].Calhoun County: Manson, 1[65].Webster County: Barnum, 1[65]; Moorland, 1[65]; no locality more definite than county, 1[65].Boone County: Pilot Mound, 3[12]; Amaqua Township, Sec. 19, 1[65].Story County: Ames, 1[65].
Minnesota.Kittson County, 1[2].Roseau County: 2-1/2 mi. SW Roseau, Jadis Township, 1[14].Itasca County: T. 61N, R. 26W, 1[102].Clay County: Moorhead, 2[9].Atkin County: Atkin, 1[50].Otter Tail County: Lake Lizzie, 1[9]; Parkers Prairie, 1[57].Grant County: 3 mi. NW Barrett, 1[76].Benton(now Mille Lacs?)County: Princeton, 1[91].Sherburne County: Elk River, 14 (6[59], 4[14], 3[91], 1[74]).Hennepin County: Fort Snelling, 6 (5[2], 1[91]).Carver? County: Chaska, 1[60].Lac qui Parle County: Madison, 5 (3[91], 2[1]); no locality more definite than county, 2 (1[68], 1[75]).Yellow Medicine County: Wood Lake, 1[2].Blue Earth County: Rapidan, 1[64].Countyin question: Moore Lake, 1[91].
Nebraska.Cuming County: Beemer, 5[91].
North Dakota.Cass County: Fargo, 1[91]; Casselton, 1[91].Dickey County: Oakes, 1[91].
South Dakota.Roberts County, 1[102].Marshall County: Fort Sisseton, 1[91].Douglas County: Armour, 1[14].Clay County, 1[102].
Long-tailed Weasel
Plates 16, 17, 18, 31, 32 and 33
Mustela longicaudaBonaparte, Charlesworth's Mag. Nat. Hist., 2:38, 1838.Putorius longicauda, Baird, Mamm. N. Amer., p. 169, 1858; Coues, Fur-bearing animals, p. 136, 1877; Bangs, Proc. Biol. Soc. Washington, 10:7, figs. 1, 1a of pls. 1, 2 and 3, February 25, 1896; Merriam, N. Amer. Fauna, 11:19, pl. 3, figs. 3, 3a, 4, 4a, pl. 5, figs. 1, 1a, text figs. 7-9, June 30, 1896.Mustela longicauda longicauda, Bailey, N. Amer. Fauna, 49:166, January 8, 1927.Mustela frenata longicauda, Hall, Carnegie Instit. Washington Publ. 473:105, November 20, 1936; Hall, Canadian Field-Nat., 52:108, October, 1938.Mustela frenata, Sowls, Journ. Mamm., 29:126, May 14, 1948.
Mustela longicaudaBonaparte, Charlesworth's Mag. Nat. Hist., 2:38, 1838.
Putorius longicauda, Baird, Mamm. N. Amer., p. 169, 1858; Coues, Fur-bearing animals, p. 136, 1877; Bangs, Proc. Biol. Soc. Washington, 10:7, figs. 1, 1a of pls. 1, 2 and 3, February 25, 1896; Merriam, N. Amer. Fauna, 11:19, pl. 3, figs. 3, 3a, 4, 4a, pl. 5, figs. 1, 1a, text figs. 7-9, June 30, 1896.
Mustela longicauda longicauda, Bailey, N. Amer. Fauna, 49:166, January 8, 1927.
Mustela frenata longicauda, Hall, Carnegie Instit. Washington Publ. 473:105, November 20, 1936; Hall, Canadian Field-Nat., 52:108, October, 1938.
Mustela frenata, Sowls, Journ. Mamm., 29:126, May 14, 1948.
Type.—Possibly not in existence. No. 43.3.3.3 [from Carlton House, Saskatchewan] in the British Museum of Natural History has been regarded by several zoölogists as the type. It is a subadult female, skull and skin, from North America. See the account ofM. erminea cicognaniifor reasons for and reasons against regarding this specimen as the holotype.No. 43.3.3.3 from the collection of Dr. John Richardson is in the white winter coat and now (Sept. 24, 1937) is prepared as a study skin. Evidences of its once having been mounted are: holes in the soles of the hind feet for supporting-wires, large straight wire in the tail, folds in the skin of the now backward-projecting hind feet, and unevenness of the skin on the back resulting from straightening out the specimen. The tip of the tail and some skin from the middle of the belly are missing. Otherwise the skin is intact. The skull is that of an animal in its first year, lacks the zygomatic arch on each side, but otherwise is complete and unbroken. The teeth all are present and entire except that p2 on the right side is missing from its alveolus.Range.—Transition and Upper Sonoran life-zones of the Great Plains, southward from central Alberta, Saskatchewan and southern Manitoba through eastern Montana, the Dakotas and Nebraska into southeastern Wyoming, northeastern Colorado and western Kansas. See figure29on page221.Characters for ready recognition.—Differs fromM. f. primulinain near (h) Clay Color rather than Brussels Brown of upper parts, least width of color of underparts more than 40 per cent of greatest width of color of upper parts, color of underparts extended onto hind foot rather than stopped short of ankle, zygomatic breadth more than 28.8 in adult males and more than 24.1 in adult females; fromM. f. spadixin lighter color being near (h) Clay Color, in males by deeper occiput in which the depth of the skull, exclusive of the sagittal crest and taken at the anterior border of the basioccipital amounts to more than 59 per cent of the mastoid breadth; fromM. f. oribasusin near (h) Clay Color rather than near (14n) Brussels Brown color of the upper parts and in males by deeper occiput in which the depth of the skull, exclusive of the sagittal crest and taken at the anterior border of the basioccipital, amounts to more than 59 per cent of the mastoid breadth; fromM. f. alleniin larger size, adult males having a total length of more than 400 millimeters, hind foot more than 45, basilar length more than 43.5, and females having a total length of more than 375 and basilar length not less than 40.0; fromM. f. nevadensisin near (h) Clay Color rather than near (14nto 1) Brussels Brown of upper parts, basilar length more than 40 in females and averaging more than 45 in males; fromM. f. neomexicanaby near (h) Clay Color rather than Buckthorn Brown color of upper parts, absence of white and Argus Brown facial markings, and length of tooth-rows amounting to more than 37 per cent of basilar length.Description.—Size.—Male: Five adults from Alberta yield average and extreme measurements as follows: Total length, 438 (418-473); length of tail, 158 (140-193); length of hind foot, 50 (46-54). Tail averages 56 per cent as long as head and body. Length of hind foot averaging more than basal length. Corresponding measurements of five adults and subadults from North Dakota are as follows: 465 (445-516); 164 (150-179); 51 (50-54). Tail averages 55 per cent as long as head and body.Female: Six adults (Alberta, 4; Saskatchewan, 1; Manitoba, 1) yield average and extreme measurements as follows: Total length, 401 (383-425); length of tail, 145 (141-159); length of hind foot, 43 (41-44). Tail averages 57 per cent as long as head and body. Length of hind foot more or less than (approximately equal to) basal length.The average differences in external measurements of the two sexes are: Total length, 37; length of tail, 13; length of hind foot, 7. General comparisons indicate that the Alberta-taken males may not attain so large a size as those from some other areas. Thus the differences in external measurements might be some greater elsewhere, say, in North Dakota.Externals.—Longest facial vibrissae black, brown or white (often all three colors in same specimen) and extending beyond ear; carpal vibrissae same color as underparts and extending to apical pad of fifth digit; hairiness of foot-soles (in summer pelage) only slightly greater than shown in figure20.Color.—Winter pelage all white except tip of tail. Summer pelage with upper parts near (h) Clay Color or near tone 3 and 4 of Snuff Brown of Oberthür and Dauthenay, pl. 303. Chin and upper lips white. Remainder of underparts ranging from near (a) Olive Ocher to near (16´) Ochraceous Buff. Upper parts of uniform color except for occasional darkening of head in front of ears. Color of underparts extends distally on posterior sides of forelegs over toes onto antipalmar faces of feet and wrists, on medial sides of hind limbs to ankles over antiplantar faces of toes and distomedial third of each tarsus, and over proximal fourth to third of under side of tail. Least width of color of underparts averaging, in a series of 10 males from Alberta, 58 (45-60) per cent of greatest width of color of upper parts. Corresponding figures for 10 females from the same place are 57 (50-74). Black tip of tail in same series of males, most of which are in full summer pelage, averaging 43 (35-60) mm. long. Thus, averaging shorter than hind foot and 27 per cent of length of tail-vertebrae.As compared withM. f. neomexicana,longicaudalacks the white facial markings, black ears, black forehead and nose, but otherwise is similarly colored. As compared withM. f. nevadensis,M. f. oribasusandM. f. spadix, each of color pattern similar tolongicauda, selected differences oflongicaudaare its much lighter color, especially of the upper parts, with less conspicuous darkening on the nose. FromM. f. primulina,longicaudadiffers in lighter color of upper parts, reddish rather than yellowish underparts, and light rather than dark-colored hind feet.Skull and teeth.—Male (based on 5 adults from Alberta): See measurements and plates16-18; weight, 4.7 (4.6-4.9) grams; basilar length, 46.0 (44.7-46.8); zygomatic breadth more than distance between condylar foramen and M1 or than between anterior palatine foramen and anterior margin of tympanic bulla; mastoid breadth more than postpalatal length; postorbital breadth less than length of upper premolars and more than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; interorbital breadth greater than distance between foramen opticum and anterior margin of tympanic bulla; breadth of rostrum more or less (usually less) than length of tympanic bulla; least width of palate less than greatest length of P4; anterior margin of tympanic bulla as far posterior to foramen ovale as width of 3 to 4 (including I3) upper incisors; height of tympanic bulla more than distance from its anterior margin to foramen ovale; length of tympanic bulla more than length of lower molar and premolar tooth-row and longer or shorter than rostrum; anterior margin of masseteric fossa below talonid of m1 or anterior half of m2.Female (based on 5 adults: Alberta, 3; N. D., 1; Sask., 1.): See measurements and plates31-33; weight, 3.1 (2.8-3.5) grams; basilar length, 42.3 (40.0-43.7); zygomatic breadth more or less (approximately equal to) than distance between condylar foramen and M1 or that between anterior palatine foramen and anterior margin of tympanic bulla; postorbital breadth less than length of upper premolars and more or less than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; least width of palate not more than greatest length of P4; tympanic bulla as far posterior to foramen ovale as width of 3 to 4 (including I3) upper incisors; height of tympanic bulla not less than distance from its anterior margin to foramen ovale; length of tympanic bulla more than length of lower molar and premolar tooth-rows and longer or shorter than rostrum.The skull of the female averages 34 per cent lighter than that of the male.Comparisons of the skull with those ofM. f. primulina,M. f. spadix,M. f. oribasus,M. f. alleni,M. f. nevadensis, andM. f. neomexicanaare made in accounts of those subspecies.
Type.—Possibly not in existence. No. 43.3.3.3 [from Carlton House, Saskatchewan] in the British Museum of Natural History has been regarded by several zoölogists as the type. It is a subadult female, skull and skin, from North America. See the account ofM. erminea cicognaniifor reasons for and reasons against regarding this specimen as the holotype.
No. 43.3.3.3 from the collection of Dr. John Richardson is in the white winter coat and now (Sept. 24, 1937) is prepared as a study skin. Evidences of its once having been mounted are: holes in the soles of the hind feet for supporting-wires, large straight wire in the tail, folds in the skin of the now backward-projecting hind feet, and unevenness of the skin on the back resulting from straightening out the specimen. The tip of the tail and some skin from the middle of the belly are missing. Otherwise the skin is intact. The skull is that of an animal in its first year, lacks the zygomatic arch on each side, but otherwise is complete and unbroken. The teeth all are present and entire except that p2 on the right side is missing from its alveolus.
Range.—Transition and Upper Sonoran life-zones of the Great Plains, southward from central Alberta, Saskatchewan and southern Manitoba through eastern Montana, the Dakotas and Nebraska into southeastern Wyoming, northeastern Colorado and western Kansas. See figure29on page221.
Characters for ready recognition.—Differs fromM. f. primulinain near (h) Clay Color rather than Brussels Brown of upper parts, least width of color of underparts more than 40 per cent of greatest width of color of upper parts, color of underparts extended onto hind foot rather than stopped short of ankle, zygomatic breadth more than 28.8 in adult males and more than 24.1 in adult females; fromM. f. spadixin lighter color being near (h) Clay Color, in males by deeper occiput in which the depth of the skull, exclusive of the sagittal crest and taken at the anterior border of the basioccipital amounts to more than 59 per cent of the mastoid breadth; fromM. f. oribasusin near (h) Clay Color rather than near (14n) Brussels Brown color of the upper parts and in males by deeper occiput in which the depth of the skull, exclusive of the sagittal crest and taken at the anterior border of the basioccipital, amounts to more than 59 per cent of the mastoid breadth; fromM. f. alleniin larger size, adult males having a total length of more than 400 millimeters, hind foot more than 45, basilar length more than 43.5, and females having a total length of more than 375 and basilar length not less than 40.0; fromM. f. nevadensisin near (h) Clay Color rather than near (14nto 1) Brussels Brown of upper parts, basilar length more than 40 in females and averaging more than 45 in males; fromM. f. neomexicanaby near (h) Clay Color rather than Buckthorn Brown color of upper parts, absence of white and Argus Brown facial markings, and length of tooth-rows amounting to more than 37 per cent of basilar length.
Description.—Size.—Male: Five adults from Alberta yield average and extreme measurements as follows: Total length, 438 (418-473); length of tail, 158 (140-193); length of hind foot, 50 (46-54). Tail averages 56 per cent as long as head and body. Length of hind foot averaging more than basal length. Corresponding measurements of five adults and subadults from North Dakota are as follows: 465 (445-516); 164 (150-179); 51 (50-54). Tail averages 55 per cent as long as head and body.
Female: Six adults (Alberta, 4; Saskatchewan, 1; Manitoba, 1) yield average and extreme measurements as follows: Total length, 401 (383-425); length of tail, 145 (141-159); length of hind foot, 43 (41-44). Tail averages 57 per cent as long as head and body. Length of hind foot more or less than (approximately equal to) basal length.
The average differences in external measurements of the two sexes are: Total length, 37; length of tail, 13; length of hind foot, 7. General comparisons indicate that the Alberta-taken males may not attain so large a size as those from some other areas. Thus the differences in external measurements might be some greater elsewhere, say, in North Dakota.
Externals.—Longest facial vibrissae black, brown or white (often all three colors in same specimen) and extending beyond ear; carpal vibrissae same color as underparts and extending to apical pad of fifth digit; hairiness of foot-soles (in summer pelage) only slightly greater than shown in figure20.
Color.—Winter pelage all white except tip of tail. Summer pelage with upper parts near (h) Clay Color or near tone 3 and 4 of Snuff Brown of Oberthür and Dauthenay, pl. 303. Chin and upper lips white. Remainder of underparts ranging from near (a) Olive Ocher to near (16´) Ochraceous Buff. Upper parts of uniform color except for occasional darkening of head in front of ears. Color of underparts extends distally on posterior sides of forelegs over toes onto antipalmar faces of feet and wrists, on medial sides of hind limbs to ankles over antiplantar faces of toes and distomedial third of each tarsus, and over proximal fourth to third of under side of tail. Least width of color of underparts averaging, in a series of 10 males from Alberta, 58 (45-60) per cent of greatest width of color of upper parts. Corresponding figures for 10 females from the same place are 57 (50-74). Black tip of tail in same series of males, most of which are in full summer pelage, averaging 43 (35-60) mm. long. Thus, averaging shorter than hind foot and 27 per cent of length of tail-vertebrae.
As compared withM. f. neomexicana,longicaudalacks the white facial markings, black ears, black forehead and nose, but otherwise is similarly colored. As compared withM. f. nevadensis,M. f. oribasusandM. f. spadix, each of color pattern similar tolongicauda, selected differences oflongicaudaare its much lighter color, especially of the upper parts, with less conspicuous darkening on the nose. FromM. f. primulina,longicaudadiffers in lighter color of upper parts, reddish rather than yellowish underparts, and light rather than dark-colored hind feet.
Skull and teeth.—Male (based on 5 adults from Alberta): See measurements and plates16-18; weight, 4.7 (4.6-4.9) grams; basilar length, 46.0 (44.7-46.8); zygomatic breadth more than distance between condylar foramen and M1 or than between anterior palatine foramen and anterior margin of tympanic bulla; mastoid breadth more than postpalatal length; postorbital breadth less than length of upper premolars and more than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; interorbital breadth greater than distance between foramen opticum and anterior margin of tympanic bulla; breadth of rostrum more or less (usually less) than length of tympanic bulla; least width of palate less than greatest length of P4; anterior margin of tympanic bulla as far posterior to foramen ovale as width of 3 to 4 (including I3) upper incisors; height of tympanic bulla more than distance from its anterior margin to foramen ovale; length of tympanic bulla more than length of lower molar and premolar tooth-row and longer or shorter than rostrum; anterior margin of masseteric fossa below talonid of m1 or anterior half of m2.
Female (based on 5 adults: Alberta, 3; N. D., 1; Sask., 1.): See measurements and plates31-33; weight, 3.1 (2.8-3.5) grams; basilar length, 42.3 (40.0-43.7); zygomatic breadth more or less (approximately equal to) than distance between condylar foramen and M1 or that between anterior palatine foramen and anterior margin of tympanic bulla; postorbital breadth less than length of upper premolars and more or less than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; least width of palate not more than greatest length of P4; tympanic bulla as far posterior to foramen ovale as width of 3 to 4 (including I3) upper incisors; height of tympanic bulla not less than distance from its anterior margin to foramen ovale; length of tympanic bulla more than length of lower molar and premolar tooth-rows and longer or shorter than rostrum.
The skull of the female averages 34 per cent lighter than that of the male.
Comparisons of the skull with those ofM. f. primulina,M. f. spadix,M. f. oribasus,M. f. alleni,M. f. nevadensis, andM. f. neomexicanaare made in accounts of those subspecies.
Remarks.—Richardson's (1829:47) account on which Bonaparte may be said to have based his name, records measurements in inches and lines which I transpose into millimeters as follows: Total length, 440 mm.; length of head and body, 305; length of tail (vertebrae), 135; length of tail (including fur), 164 mm. Specimen no. 43.3.3.3 in the British Museum, which has by some persons been regarded as the type, yields measurements as follows: Total length, 408 (which allows for 15 mm. loss of the fleshy part of the end of the tail); length of head and body, 272; length of tail (vertebrae), 136 (= 121 + 15); length of tail (including fur), 162 (142 + 20 mm. that appears to have been lost). Richardson's specimen would appear to have been of unusual proportions and to have been larger than no. 43.3.3.3. Some reasons for and reasons against regarding this specimen as the holotype are given in the account ofM. erminea cicognanii.
The namelongicaudawas applied to practically all long-tailed weasels of the western United States at one time but as one after another of the geographic variants in the mountainous regions were designated as separable, the namelongicaudacame to be restricted to the light-colored, relatively large, animal of the Great Plains.
The intergradation oflongicaudawithspadixandoribasushas been commented on in the discussions of those subspecies. The larger size and darker color of specimens referred tolongicaudafrom Devils Lake and Grafton, North Dakota, are features indicative of intergradation there withspadix. Two young females from Waterton Lake Park, Alberta, by their darker than average color, suggest intergradation withoribasus, as, for that matter, does the specimen from Waterton Lake [= Chief Mountain Lake, in Montana] itself, which, however, is even darker than the two specimens taken on the Canadian side of the line and hence is referred tooribasus. An adult female, no. 175586, U. S. Nat. Mus., from Moose Pass, Alberta, examined after the above was written, is larger than any other female seen oflongicaudaand in this respect may show approach tooribasus, which in the northern part of its range is of large size as judged by males from the Bowron Lake region.
One male, no. 8564, Nat. Mus. Canada, from Max Lake, Turtle Mountain, Manitoba, presents puzzling characters. The external measurements of 465, 170, and 57, are in keeping with the great length of the skull which has a basilar length of 48.8. The tooth-rows are 19.3 in length and the mastoid breadth, 25.4. The relative narrowness indicated by the mastoid breadth is maintained throughout the skull. The only other specimens relating to the Turtle Mountains that have been seen are two male, skins without measurements or corresponding skulls, nos. 38902 and 38903, Amer. Mus. Nat. Hist., labeled as from either "Stump Lake or Turtle Mts.," North Dakota. One of these, no. 38902, is much darker than the other. Possibly it is from the Turtle Mountains and the other, lighter-colored one, is from Stump Lake. Study of additional specimens from the Turtle Mountains might show the existence there of a distinct race.
Four specimens, in the collection of Myron Swenk, from Inland, Clay County, Nebraska, are instructive as showing how intergradation occurs betweenprimulinaandlongicauda. A subadult male, no. 10, is intermediate in external measurements and in color but in each instance is nearerprimulina. The same is true of the least width of the color of the underparts. The color of the underparts extends uninterruptedly over the hind legs to the toes as inlongicauda, but is absent from the underside of the tail as inprimulina. In the skull, the basilar length, breadth of bulla, and size of teeth are nearerlongicauda, as are also the ratios to the basilar length of the length of tooth-rows, breadth of the rostrum, length of the tympanic bulla, and depth of the braincase at the anterior margin of the basioccipital. Ratios to the basilar length of the interorbital breadth, mastoid breadth, zygomatic breadth, and depth of the skull at the posterior borders of the upper molars are nearer to those ofprimulina. The relatively long rostrum, as represented by the orbitonasal length, is nearest to that ofspadix. A young, almost subadult, female, no. 7, agrees withprimulinain color, color pattern, and length of hind foot. The other external measurements are intermediate, but nearer those ofprimulina. Size of skull and teeth are as inlongicauda. Relative proportions of parts of the skull are not diagnostic in specimens as young as this female. An adult female, skull only, no. 8, agrees with, or approaches nearer to,longicaudain size of skull and teeth and in relative proportion of every part studied. A juvenile, skull only, of questionable sex, no. 9, provides no diagnostic characters. On the basis of color, these specimens from Inland are distinctly nearerprimulina. On the basis of cranial characters they are distinctly nearerlongicauda. External measurements are intermediate and are a little nearer those ofprimulina. By placing the most weight on the cranial characters, the animals may be referred tolongicauda. The same may be said of 2 skins, one skin with a skull, from Hastings, Nebraska. In each skin the color-pattern is as inprimulina; in one the under side of the tail is nevertheless lighter-colored more as inlongicaudaand the skull, adult male 121651 American Museum of Natural History, approaches nearer toprimulinain narrowness but has the large teeth oflongicauda.
Intergradation withneomexicanais suggested by one specimen, no. 7936, Univ. Kans., from Thomas County, Kansas, which has well-developed white facial markings.
The specimen, no. 180, Kansas Agric. College, from Glasco, is mounted, of large size, in white winter pelage, and lacks external measurements. On the basis of its obvious large size, and a hind foot measurement of 49 millimeters obtained from the mounted skin, the animal is provisionally referred tolongicaudarather than toprimulina.
Putorius culbertsoniis a name now credited to Coues (1877:136). Although Coues probably intended only to indicate that Baird wrote this name on the labels of two specimens in the mammal collection of the Smithsonian Institution, Coues gave an "indication" of the application of the name by publishing at the same time the catalogue numbers of specimens whose labels bore the name and thus, in accordance with article 21 of the International Rules of Zoölogical Nomenclature, himself becomes the author of the name. Of the two specimens mentioned by Coues, only the first recorded by him, no. 4320 (with skull no. 37995, U. S. Nat. Mus.), can now be found.
Fortunately, the skull of this specimen labeled (see Lyon and Osgood, 1909:218) as taken at Fort Laramie, Wyoming, is well preserved. Its only defects are a fracture in the left zygomatic arch and the absence of parts of each of the first lower molars. In deciding on the subspecific application of the namePutorius culbertsoniCoues, the skull of the type must be principally relied upon, for there is available only one other specimen, a skin only (no. 12596, U. S. Nat. Mus.), from the same place, and it, like the type, is in white winter pelage and lacks flesh measurements.
The ranges as now known of three subspecies ofMustela frenataapproach near to Fort Laramie. These areM. f. longicauda,M. f. alleni, andM. f. nevadensis. The skull of the type ofculbertsoniis not typical of any one of the three mentioned races. The small size of its teeth and relative (to basilar length) shallowness of the frontal region of the skull through the postorbital processes of the frontal are as innevadensis. The zygomatic arches are not so greatly expanded as in some specimens oflongicaudaand are more like the average fornevadensisoralleni, as also is the relatively (to basilar length) long orbitonasal length. However, each of these characters is subject to variation and alone is not surely diagnostic, especially toward the margin of the range of any one of the subspecies concerned. The same may be said of the relatively great breadth of the skull interorbitally—a feature typically found inlongicauda. More important, in my estimation, is the large size of the skull; all parts measured (excepting the teeth, the depth at the posterior border of the last upper molars, the zygomatic breadth, and the depth of the tympanic bullae) equal or approach nearest to the average for males oflongicaudaof similar age.
The small size ofalleniprevents its identification withculbertsoni. The question of application lies betweennevadensisandlongicauda. If the long-tailed weasel at Fort Laramie is found to be referable to the race earlier namedlongicauda, no change in current nomenclature will be effected. If, on the other hand, the long-tailed weasel from Fort Laramie is found to be referable tonevadensisthis name will have to fall before the earlier proposed nameculbertsoni. There is, however, a third possibility, namely, that the long-tailed weasel of the Transition and Upper Sonoran zones of southern Wyoming and northern Colorado, as for example, at Lay, Colorado, may represent a recognizable race characterized by size about as inlongicauda, relative proportions of skull about as innevadensisand coloration intermediate, to which the nameculbertsonimay apply. For more detailed discussion of this possibility, see remarks underM. f. nevadensis.
Satisfactory application of the namePutorius culbertsoniCoues requires an adequate series of adult specimens, of both sexes in the summer coat with external measurements taken in the flesh, from the type locality and like material from elsewhere in southern Wyoming. On the evidence furnished by the skull of the type ofculbertsoni, that name tentatively is placed in the synonomy oflongicauda.
Only 2 of 25 adults examined for malformation of the frontal sinuses by parasites showed evidence of disease.
Specimens examined.—Total number, 138, arranged alphabetically by provinces and states and further by districts or counties from north to south except as otherwise indicated. Unless otherwise indicated specimens are in the collection of the United States National Museum.Alberta.St. Albert, 1; S. Edmonton, 3; Islay, 4[77]; Battle River, south of Camrose, 1[77]; Daysland, 1[77]; Moose Pass, 1; Blindman River, 2 (1[75], 1[2]); Red Deer, 3 (2[2], 1[60]); Bearberry Creek near Sundre, 1[77]; Canad. Nat. Park, N.W. Territory, 1[60]; Red Deer River, Didsbury, 1; Canmore, 1; Calgary, 11 (6[60], 2[1], 1[86]); Red Deer River, 3[2]; Little Sandhill Creek, Red Deer River, 1[77]; Waterton Lake Park, 2[77]; Sweetgrass Hills, 1[77]; Alberta, 1[14].Colorado.Yuma County: Wray 4 (1[88], 3[74]).Kansas.Rawlins County: 7 mi. N, 3 mi. W Beardsley, 1[74]; 6 mi. S and 2 mi. E Atwood, 1[74]; 15 mi. SE Atwood, 1[74].Thomas County: near Brewster, 2[93]; no locality more definite than county, 2[93].Trego County, 2 (1[2]).Cloud County: Glasco, 1[67].Manitoba.Portage la Prairie, 3[75]; Carberry, 2 (1[2], 1[1]); Carman, 1[60]; Max Lake, Turtle Mt., 1[77].Montana.Glacier County: St. Marys Lake, 1; Blackfoot, 1: Blackfoot Agency, 1.Blaine County: 6 mi. east Chinook, 1[74].Pondera County: 1/2 mi. SE Conrad, 1[74].Toole County: Shelby Junction, 1.Hill County: Havre, 1.Fergus County: Moccasin Mts., 5 mi. NW Hilger, 1; 7 mi. NE Hilger, 1.Rosebud County: 3/4 mi. N Ingomar, 1.Countyin question, Milk River, 2.Nebraska.Dawes County: Chadron, 2[35].Cherry County: Kennedy, 1; no locality more definite than county, 1.Brown County: Long Pine, 1[68].Antelope County: Neligh, 1[35].Adams County: Hastings, 2[2].Clay County: Inland, 4[35].North Dakota(arranged by counties from west to east).Divide County: Crosby, 1.Mountrail County: Lostwood, 1. Little Missouri River, 1.Golden Valley County: Sentinel Butte, 1.Billings County: Medora, 1[60].McLean County: 3 mi. W Elbowoods, 1.Oliver County: Ft. Clark, 2.Morton County: Mandan, 1.Sioux County: 3 mi. N Cannonball, 1.Logan County: 6 mi. SW Napoleon, 1.Rolette County: Turtle Mts., 1[76]; Fish Lake, 1.Benson County: Ft. Totten, 3[14]; Sully Hill Nat. Park, 1.Ramsey County: Devils Lake, 2. Stump Lake or Turtle Mts., 2[2].Nelson County: Stump Lake, 1.Grand County: Larimore, 1.Walsh County: Grafton, 11 (4[76], 3[74], 2[2]).Stutsman County: Jamestown, 1.Barnes County: Valley City, 1.Saskatchewan.Wingard, 5; Osier, 2[75]; Simpson, 1[2]; Touchwood Hills, 4[7]; South arm Last Mountain Lake, 1[77]; Rush Lake (Assiniboia, N.W.T.), 2[75].South Dakota.Pennington County: Rapid City, 1.Wyoming.Goshen County: Fort Laramie, 2.
Specimens examined.—Total number, 138, arranged alphabetically by provinces and states and further by districts or counties from north to south except as otherwise indicated. Unless otherwise indicated specimens are in the collection of the United States National Museum.
Alberta.St. Albert, 1; S. Edmonton, 3; Islay, 4[77]; Battle River, south of Camrose, 1[77]; Daysland, 1[77]; Moose Pass, 1; Blindman River, 2 (1[75], 1[2]); Red Deer, 3 (2[2], 1[60]); Bearberry Creek near Sundre, 1[77]; Canad. Nat. Park, N.W. Territory, 1[60]; Red Deer River, Didsbury, 1; Canmore, 1; Calgary, 11 (6[60], 2[1], 1[86]); Red Deer River, 3[2]; Little Sandhill Creek, Red Deer River, 1[77]; Waterton Lake Park, 2[77]; Sweetgrass Hills, 1[77]; Alberta, 1[14].
Colorado.Yuma County: Wray 4 (1[88], 3[74]).
Kansas.Rawlins County: 7 mi. N, 3 mi. W Beardsley, 1[74]; 6 mi. S and 2 mi. E Atwood, 1[74]; 15 mi. SE Atwood, 1[74].Thomas County: near Brewster, 2[93]; no locality more definite than county, 2[93].Trego County, 2 (1[2]).Cloud County: Glasco, 1[67].
Manitoba.Portage la Prairie, 3[75]; Carberry, 2 (1[2], 1[1]); Carman, 1[60]; Max Lake, Turtle Mt., 1[77].
Montana.Glacier County: St. Marys Lake, 1; Blackfoot, 1: Blackfoot Agency, 1.Blaine County: 6 mi. east Chinook, 1[74].Pondera County: 1/2 mi. SE Conrad, 1[74].Toole County: Shelby Junction, 1.Hill County: Havre, 1.Fergus County: Moccasin Mts., 5 mi. NW Hilger, 1; 7 mi. NE Hilger, 1.Rosebud County: 3/4 mi. N Ingomar, 1.Countyin question, Milk River, 2.
Nebraska.Dawes County: Chadron, 2[35].Cherry County: Kennedy, 1; no locality more definite than county, 1.Brown County: Long Pine, 1[68].Antelope County: Neligh, 1[35].Adams County: Hastings, 2[2].Clay County: Inland, 4[35].
North Dakota(arranged by counties from west to east).Divide County: Crosby, 1.Mountrail County: Lostwood, 1. Little Missouri River, 1.Golden Valley County: Sentinel Butte, 1.Billings County: Medora, 1[60].McLean County: 3 mi. W Elbowoods, 1.Oliver County: Ft. Clark, 2.Morton County: Mandan, 1.Sioux County: 3 mi. N Cannonball, 1.Logan County: 6 mi. SW Napoleon, 1.Rolette County: Turtle Mts., 1[76]; Fish Lake, 1.Benson County: Ft. Totten, 3[14]; Sully Hill Nat. Park, 1.Ramsey County: Devils Lake, 2. Stump Lake or Turtle Mts., 2[2].Nelson County: Stump Lake, 1.Grand County: Larimore, 1.Walsh County: Grafton, 11 (4[76], 3[74], 2[2]).Stutsman County: Jamestown, 1.Barnes County: Valley City, 1.
Saskatchewan.Wingard, 5; Osier, 2[75]; Simpson, 1[2]; Touchwood Hills, 4[7]; South arm Last Mountain Lake, 1[77]; Rush Lake (Assiniboia, N.W.T.), 2[75].
South Dakota.Pennington County: Rapid City, 1.
Wyoming.Goshen County: Fort Laramie, 2.
Long-tailed Weasel
Plates16,17,18,31,32,33and40
Putorius (Arctogale) longicauda oribasusBangs, Proc. New England Zoöl. Club, 1:81, December 27, 1899.Putorius longicauda, Coues, Fur-bearing animals, p. 136, 1877 (part).Mustela longicauda oribasus, Miller, U. S. Nat. Mus. Bull., 79:98, December 31, 1912.Mustela longicauda oribasa, Hall, Univ. California Publ. Zoöl., 40:368, November 5, 1934.Mustela frenata oribasa, Hall, Carnegie Instit. Washington Publ. 437:105, November 20, 1936.
Putorius (Arctogale) longicauda oribasusBangs, Proc. New England Zoöl. Club, 1:81, December 27, 1899.
Putorius longicauda, Coues, Fur-bearing animals, p. 136, 1877 (part).
Mustela longicauda oribasus, Miller, U. S. Nat. Mus. Bull., 79:98, December 31, 1912.
Mustela longicauda oribasa, Hall, Univ. California Publ. Zoöl., 40:368, November 5, 1934.
Mustela frenata oribasa, Hall, Carnegie Instit. Washington Publ. 437:105, November 20, 1936.
Type.—Female, adult, skull and skin; no. 9058, collection of E. A. and O. Bangs, but now in collection of Mus. Comp. Zoöl.; source of Kettle River, 7500 feet [the summit between middle fork of Kettle River and Cherry Creek at Pinnacles—oral information from the collector, Feb. 12, 1936], British Columbia; September 10, 1898; obtained by Allan Brooks; original no. 1368.The skull (plate40) is complete and unbroken. The teeth all are present and entire except right I3which has the anterior half broken away. The skin is complete, fairly well made, and in summer pelage.Range.—Canadian and Hudsonian life-zones from near 56°N in the Rocky Mountains of British Columbia and Alberta and Ootsa Lake along the Fraser and Chilcotin rivers south to Alta Lake, in the Caribou and Monashee mountains, probably in the Selkirks and Rockies, and through the Rockies of Montana into extreme northern Wyoming. See figure29on page221.Characters for ready recognition.—Differs fromM. f. longicaudaby near (14n) Brussels Brown rather than near (h) Clay Color of upper parts and in males by relatively shallower occiput in which the depth of the skull, exclusive of the sagittal crest and taken at the anterior border of the basioccipital, amounts to less than 59 per cent of the mastoid breadth; fromM. f. nevadensisby greater average size, see measurements.Description.—Size.—Male: Two adults from Florence, Montana, measure as follows: Total length, 440, 440; length of tail, 165, 161; length of hind foot, 47, 49. Corresponding measurements of an adult male from Quesnel, British Columbia, are: 443; 168; 55. Tail amounts to 60, 58, and 61 per cent as long as head and body. Length of hind foot averages more than basal length.Female: The type specimen, the only typical adult or subadult specimen of this sex of which external measurements are available, measures: Total length, 392, length of tail, 150, length of hind foot, 46. Tail is 63 per cent as long as head and body. Length of hind foot amounts to more than basal length.The differences in external measurements, between the one female and the average of the three males are: Total length, 49; length of tail, 15; length of hind foot, 4.Externals.—Longest facial vibrissae brown or white (often both colors in same specimen) and extending beyond ear; carpal vibrissae same color as underparts and extending to or beyond apical pad of fifth digit; hairiness of foot-soles (in summer pelage) slightly less than shown in figure19.Color.—Upper parts, in summer, near (14n) Brussels Brown, more blackish and less reddish than tone 4 of Burnt Umber of Oberthür and Dauthenay, pl. 304; in type near tone 4, pl. 301 of Oberthür and Dauthenay. Underparts, in summer, Buff Yellow or near (20c) Amber Yellow. In winter, all white except tip of tail which is at all times black. Upper parts of uniform color except for occasional slight darkening of top of head and along mid-dorsal line of back. Color of underparts extends distally on posterior sides of forelegs over feet, on medial sides of hind limbs over antiplantar faces of toes and over proximal two-thirds of ventral side of tail. Least width of color of underparts amounting to 43 per cent of greatest width of color of upper parts, 75 per cent in male from 4 miles northeast of Quesnel, British Columbia, and 52 (33-66) in four males from Montana. Black tip of tail in four males from Montana averaging 50 (44-60) mm. long. Thus averaging approximately as long as hind foot and 33 per cent of length of tail-vertebrae.Color not different than in many specimens ofM. f. nevadensis. Color comparison withM. f. longicaudahas been made in the account of that subspecies.Skull and teeth.—Male (based on 5 adults and 2 subadults from British Columbia and 4 adults from Montana): See measurements and plates16-18. As described inMustela frenata longicaudaexcept that: Weight, 5.0 (3.8-6.0) grams; basilar length, 46.7 (43.6-48.8); postorbital breadth in one of nine instances less than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; interorbital breadth more or less than distance between foramen opticum and anterior margin of tympanic bulla; breadth of rostrum less than length of tympanic bulla; anterior margin of tympanic bulla as far posterior to foramen ovale as width of 2-1/2 to 5 upper incisors; length of tympanic bulla not less than length of lower molar and premolar tooth-row and shorter than rostrum.Female (based on the type, specimen): See measurements and plates31-33, 40. As described inMustela frenata longicaudaexcept that: Weight, 3.5 grams; basilar length, 41.6 mm.; zygomatic breadth more than distance between anterior palatine foramen and anterior margin of tympanic bulla; postorbital breadth more than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; least width of palate more than outside length of P4; tympanic bulla as far posterior to foramen ovale as width of 4-1/2 upper incisors; height of tympanic bulla less than distance from anterior margin of tympanic bulla to foramen ovale; length of tympanic bulla less than length of rostrum. If more than one skull were available of the female oforibasusit is believed that the description would agree with that oflongicaudain nearly all features.The skull of the female is 30 per cent lighter than that of the average male.
Type.—Female, adult, skull and skin; no. 9058, collection of E. A. and O. Bangs, but now in collection of Mus. Comp. Zoöl.; source of Kettle River, 7500 feet [the summit between middle fork of Kettle River and Cherry Creek at Pinnacles—oral information from the collector, Feb. 12, 1936], British Columbia; September 10, 1898; obtained by Allan Brooks; original no. 1368.
The skull (plate40) is complete and unbroken. The teeth all are present and entire except right I3which has the anterior half broken away. The skin is complete, fairly well made, and in summer pelage.
Range.—Canadian and Hudsonian life-zones from near 56°N in the Rocky Mountains of British Columbia and Alberta and Ootsa Lake along the Fraser and Chilcotin rivers south to Alta Lake, in the Caribou and Monashee mountains, probably in the Selkirks and Rockies, and through the Rockies of Montana into extreme northern Wyoming. See figure29on page221.
Characters for ready recognition.—Differs fromM. f. longicaudaby near (14n) Brussels Brown rather than near (h) Clay Color of upper parts and in males by relatively shallower occiput in which the depth of the skull, exclusive of the sagittal crest and taken at the anterior border of the basioccipital, amounts to less than 59 per cent of the mastoid breadth; fromM. f. nevadensisby greater average size, see measurements.
Description.—Size.—Male: Two adults from Florence, Montana, measure as follows: Total length, 440, 440; length of tail, 165, 161; length of hind foot, 47, 49. Corresponding measurements of an adult male from Quesnel, British Columbia, are: 443; 168; 55. Tail amounts to 60, 58, and 61 per cent as long as head and body. Length of hind foot averages more than basal length.
Female: The type specimen, the only typical adult or subadult specimen of this sex of which external measurements are available, measures: Total length, 392, length of tail, 150, length of hind foot, 46. Tail is 63 per cent as long as head and body. Length of hind foot amounts to more than basal length.
The differences in external measurements, between the one female and the average of the three males are: Total length, 49; length of tail, 15; length of hind foot, 4.
Externals.—Longest facial vibrissae brown or white (often both colors in same specimen) and extending beyond ear; carpal vibrissae same color as underparts and extending to or beyond apical pad of fifth digit; hairiness of foot-soles (in summer pelage) slightly less than shown in figure19.
Color.—Upper parts, in summer, near (14n) Brussels Brown, more blackish and less reddish than tone 4 of Burnt Umber of Oberthür and Dauthenay, pl. 304; in type near tone 4, pl. 301 of Oberthür and Dauthenay. Underparts, in summer, Buff Yellow or near (20c) Amber Yellow. In winter, all white except tip of tail which is at all times black. Upper parts of uniform color except for occasional slight darkening of top of head and along mid-dorsal line of back. Color of underparts extends distally on posterior sides of forelegs over feet, on medial sides of hind limbs over antiplantar faces of toes and over proximal two-thirds of ventral side of tail. Least width of color of underparts amounting to 43 per cent of greatest width of color of upper parts, 75 per cent in male from 4 miles northeast of Quesnel, British Columbia, and 52 (33-66) in four males from Montana. Black tip of tail in four males from Montana averaging 50 (44-60) mm. long. Thus averaging approximately as long as hind foot and 33 per cent of length of tail-vertebrae.
Color not different than in many specimens ofM. f. nevadensis. Color comparison withM. f. longicaudahas been made in the account of that subspecies.
Skull and teeth.—Male (based on 5 adults and 2 subadults from British Columbia and 4 adults from Montana): See measurements and plates16-18. As described inMustela frenata longicaudaexcept that: Weight, 5.0 (3.8-6.0) grams; basilar length, 46.7 (43.6-48.8); postorbital breadth in one of nine instances less than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; interorbital breadth more or less than distance between foramen opticum and anterior margin of tympanic bulla; breadth of rostrum less than length of tympanic bulla; anterior margin of tympanic bulla as far posterior to foramen ovale as width of 2-1/2 to 5 upper incisors; length of tympanic bulla not less than length of lower molar and premolar tooth-row and shorter than rostrum.
Female (based on the type, specimen): See measurements and plates31-33, 40. As described inMustela frenata longicaudaexcept that: Weight, 3.5 grams; basilar length, 41.6 mm.; zygomatic breadth more than distance between anterior palatine foramen and anterior margin of tympanic bulla; postorbital breadth more than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; least width of palate more than outside length of P4; tympanic bulla as far posterior to foramen ovale as width of 4-1/2 upper incisors; height of tympanic bulla less than distance from anterior margin of tympanic bulla to foramen ovale; length of tympanic bulla less than length of rostrum. If more than one skull were available of the female oforibasusit is believed that the description would agree with that oflongicaudain nearly all features.
The skull of the female is 30 per cent lighter than that of the average male.