Comparison withlongicaudareveals that, on the average, skulls of males are larger, relative to the basilar length broader across the mastoids, shallower through the braincase as measured at the anterior end of the basioccipital exclusive of the sagittal crest, with longer rostrum. Compared withnevadensis, the skull averages larger in all measurements taken, and has a relatively broader rostrum, relatively greater mastoid breadth and a braincase which is shallower relative to the basilar length. By weight, the skull ofnevadensisis a fourth lighter, and in linear measurements 5 to 18 per cent smaller.
Remarks.—Some of the specimens from Montana, which here are referred tooribasus, more than half a century ago were listed by Coues (1877:138) under the namelongicauda. It was not until 1899 that this race was given a name by Bangs, who at that time (1899B:81) accurately made out the distinctive color features. Distinctive cranial characters cannot be described with assurance even now because there still are too few specimens.
The type specimen, at one time examined by the present writer, has on the stuffed skin no well-developed mammae, scrotal pouch, or other visible sexual part. Probably the collector's sex mark for female is correct.
As judged by the two skulls of subadult males from the Barkerville region, individuals of this race attain larger size than do those oflongicauda. On the basis of larger size than eitherlongicaudaornevadensis, the specimens from the Rocky Mountains of Montana and two from northern Wyoming are referred to this race. The short, wide, flat, tympanic bullae, relatively great mastoidal breadth, and some other features of the specimen from Donovan, Montana, point towardoribasus, whereas nearly as many more cranial features, in this instance mainly differences in size, are indicative ofnevadensisto which race the specimen might almost equally well be referred. Another male from Darby, in the Bitterroot Valley of Montana, has a slightly longer hind foot than those from Florence, but a female from Hamilton, agrees more nearly withnevadensis. The average of all the specimens from the Bitterroot Valley is a little neareroribasus. Four skulls from Buffalo, Wyoming, here referred tonevadensisshow approach tooribasusin size of skull. The specimens from Big Snowy Mountains, and the Highwood Mountains of Montana are too young clearly to show size of the adult skull, but are distinctly darker colored thanlongicaudaof the plains country proper. Of two subadult females from Tacy, Montana, the color of the one in summer pelage is distinctly nearer that oforibasusandnevadensisthan it is to that oflongicaudato which some approach in color might be expected. The reduced size of both of the specimens is further suggestive ofnevadensisand it may be that adult specimens from these more eastern mountainous areas in Montana will show thatnevadensisis the name proper to apply to animals of this region.
Intergradation withnevadensisis suggested by specimens collected from along the upper reaches of Okanagan Lake, British Columbia, by Major Allan Brooks and Mr. J. A. Munro and by a series of skulls from Ione, Pend Orielle County, Washington, lent me by Mr. Walter Dalquest. At each place, the average of all specimens is nearest to that ofnevadensis.
Specimens from near Waterton Lake show several steps in the transition from the light-coloredlongicaudatype of coloration to the darker coloration characterizingoribasus. One taken here, at a time when the body of water referred to seems to have been known as Chief Mountain Lake, is barely dark enough to be placed withoribasus. Two other specimens from across the Canadian Border labeled as "Waterton Lake Park" are slightly lighter colored above, and on this account are placed withlongicauda.
The two adult males from Lillooet, British Columbia, are referable tooribasusalthough neither is quite typical. One has a saturated coloration suggestive of that ofaltifrontalisand the skull is shorter and broader than in other specimens oforibasus. The female from Lillooet, skin alone, no. 916, Prov. Mus., B. C. is small fororibasus. The female, no. 1539, collection of Kenneth Racey, from Alta Lake, in brown winter pelage, in almost every measurement falls nearly midway betweenaltifrontalisandoribasusbut slightly nearer the latter. The skull from Chezacut and 3 animals from Wistaria, British Columbia, probably are females and show a greater average size than specimens from farther to the southeast. For example, the basilar length of the skull, 44.8 (44.3 to 45.1), exceeds that of the type specimen. The animals from Wistaria on Ootsa Lake furnish the northwesternmost station of occurrence of which I have record for this subspecies.
The northernmost records of occurrence, at "Clearwater River, Peace River, B. C," and at Little Prairie, are furnished by a white skin without skull, no. 257450, U. S. Nat. Mus., purchased on August 2, 1932, at the place mentioned by W. H. Sheldon and Richard Borden, and a skull with white winter skin, no. 3585, Provincial Museum, British Columbia, respectively. The characters distinguishinglongicaudaandoribasusare not shown by white winter skins; the skull shows some features oflongicauda, and the reference of these specimens tooribasusrather thanlongicaudais tentative.
Only the skull from Little Prairie shows evidence of infestation of the frontal sinuses by parasites. In the Barkerville area of British Columbia, Mr. and Mrs. Thomas T. McCabe obtained only 2 skulls of this subspecies from a total of 238 weasel skulls gathered by local trappers. The others wereMustela erminea.
Specimens examined.—Total number, 46, listed by localities from north to south and unless otherwise indicated, in the United States National Museum.British Columbia.West of Hudson Hope, 1[7]; Clearwater River, tributary to Peace River, 1; Little Prairie, a few miles south of Peace River and about 40 miles west of the main highway between Dawson Creek and Fort St. John, 1[85]; Wistaria, 3[85]; Four Mile Creek, 4 mi. NE Quesnel, 1[21]; Isaacs Lake, 3200 ft., 1[74]; Barkerville region, 1[74]; Clear River, 4800 ft., 1[74]; Chezacut, 1[31]; Lillooet 3 (2[77], 1[85]); Alta Lake, 1[31]; source of Kettle River, 7500 ft., 1[75]; E side Beaverfoot Range, 4000 to 4500 ft. between Fraser Creek and 6 mi. SE of Fraser Creek, 1[74]; Cranbrook, 1[86]; head of Cross River, 10 mi. below Assiniboine Pass, 1[7]; camp east of "Kootanie," 1[7]; camp east of Kootanie River, 1[7].Alberta.Thoral Creek, 7000 ft., 50 mi. NE Jasper, 1[2].Montana.Glacier? County: Chief Mt. Lake (= Waterton Lake), 1.Flathead County: Columbia Falls, 1.Chouteau? County: Highwood Mts., 1.Fergus? County: Big Snowy Mts., 1.Wheatland County: Harlowton, 1[74].Ravalli County: Florence, 2; Hamilton, 1[56]; Darby, 1[56]; Carlos [= Charlos] Heights, 2[74]; Tin Cup District, 2[74]; no locality more definite than county, 2[74].Beaverhead County: Donovan, 1.Madison County: Sheridan, 1[74].Gallatin County: Ranch 7-11, Eldridge, 1[60].Stillwater County: Tacy, 2[76].Countyin question: Gallatin Valley, 1; Yellowstone Park, 1[75].Wyoming.Glen Creek, Mammoth Hot Springs, 1.Park County: Four Bears, 1[2].
Specimens examined.—Total number, 46, listed by localities from north to south and unless otherwise indicated, in the United States National Museum.
British Columbia.West of Hudson Hope, 1[7]; Clearwater River, tributary to Peace River, 1; Little Prairie, a few miles south of Peace River and about 40 miles west of the main highway between Dawson Creek and Fort St. John, 1[85]; Wistaria, 3[85]; Four Mile Creek, 4 mi. NE Quesnel, 1[21]; Isaacs Lake, 3200 ft., 1[74]; Barkerville region, 1[74]; Clear River, 4800 ft., 1[74]; Chezacut, 1[31]; Lillooet 3 (2[77], 1[85]); Alta Lake, 1[31]; source of Kettle River, 7500 ft., 1[75]; E side Beaverfoot Range, 4000 to 4500 ft. between Fraser Creek and 6 mi. SE of Fraser Creek, 1[74]; Cranbrook, 1[86]; head of Cross River, 10 mi. below Assiniboine Pass, 1[7]; camp east of "Kootanie," 1[7]; camp east of Kootanie River, 1[7].
Alberta.Thoral Creek, 7000 ft., 50 mi. NE Jasper, 1[2].
Montana.Glacier? County: Chief Mt. Lake (= Waterton Lake), 1.Flathead County: Columbia Falls, 1.Chouteau? County: Highwood Mts., 1.Fergus? County: Big Snowy Mts., 1.Wheatland County: Harlowton, 1[74].Ravalli County: Florence, 2; Hamilton, 1[56]; Darby, 1[56]; Carlos [= Charlos] Heights, 2[74]; Tin Cup District, 2[74]; no locality more definite than county, 2[74].Beaverhead County: Donovan, 1.Madison County: Sheridan, 1[74].Gallatin County: Ranch 7-11, Eldridge, 1[60].Stillwater County: Tacy, 2[76].Countyin question: Gallatin Valley, 1; Yellowstone Park, 1[75].
Wyoming.Glen Creek, Mammoth Hot Springs, 1.Park County: Four Bears, 1[2].
Long-tailed Weasel
Plates18,19,20,31,32and33
Putorius alleniMerriam, N. Amer. Fauna, 11:24, June 30, 1896.Mustela alleni, Miller, U. S. Nat. Mus. Bull., 79:99, December 31, 1912.Mustela frenata alleni, Hall, Carnegie Instit. Washington Publ. 473:106, November 20, 1936.
Putorius alleniMerriam, N. Amer. Fauna, 11:24, June 30, 1896.
Mustela alleni, Miller, U. S. Nat. Mus. Bull., 79:99, December 31, 1912.
Mustela frenata alleni, Hall, Carnegie Instit. Washington Publ. 473:106, November 20, 1936.
Type.—Male, adult, skull and skin; no. 186451, U. S. Nat. Mus. (formerly 4485/5120, collection of Dr. C. Hart Merriam); Custer, South Dakota; obtained by Vernon Bailey; original no. 90.The skull is complete and unbroken. The upper incisors are missing. All the other teeth are present although the premolars, and especially the canines, are much worn, possibly as the result of the animal's efforts to free itself from a trap. The skin is fairly well made, in a good state of preservation, and entire.Range.—Canadian, Transition and Upper Sonoran life-zones of the Black Hills of South Dakota and adjacent semi-bad-land territory of Wyoming and Nebraska southward to Mitchell, Scottsbluff County. See figure29on page221.Characters for ready recognition.—Differs fromM. f. longicaudain smaller size, adult males having a total length of less than 400, hind foot less than 45, basilar length less than 43.5, and in adult females total length less than 375, and basilar length less than 40; fromM. f. nevadensisin near Clay Color rather than near (14ntol) Brussels Brown of upper parts in summer.Description.—Size.—Male: External measurements of the type specimen are: Total length, 372; length of tail, 137; length of hind foot, 44. Tail is 58 per cent as long as head and body. Length of hind foot more than basal length.Female: No external measurements for typical adults are available. No. M1 #41 from Mitchell, Scottsbluff Co., Nebraska, an adult female which is an intergrade with the largerM. f. longicauda, measures as follows: Total length, 367; length of tail, 120; length of hind foot, 41.Externals.—Longest facial vibrissae dark brown or white 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) as shown in figure20.Color.—Winter pelage unknown; probably white except, of course, tip of tail. Summer pelage as described inMustela frenata longicaudaexcept that: Least width of color of underparts averaging, in 3 males from Black Hills, 54 (38-62) per cent of greatest width of color of upper parts. Black tip of tail averaging 43 (40-45) mm. long. Thus, averaging approximately same length as hind foot and in type specimen amounting to 33 per cent of length of tail-vertebrae.Skull and teeth.—Male (based on the type and no. 7440 Amer. Mus. Nat. Hist., from Hill City, S. Dak.): See measurements and plates18-20. As described inMustela frenata longicaudaexcept that: Weight, 3.1 (3.0-3.2) grams; basilar length, 41.0 (40.9-41.0); mastoid breadth not less than postpalatal length; breadth of rostrum more than length of P4; anterior margin of tympanic bulla as far posterior to foramen ovale as width of 4 to 5 upper incisors; height of tympanic bulla more or less than distance from its anterior margin to foramen ovale.Female (based on no. 7441, American Mus. Nat. Hist., from Black Hills, S. Dak.): See measurements and plates31-33. As described inMustela frenata longicaudaexcept that: Weight, 2.0 grams; basilar length 37.6. The skull of the female is 35 per cent lighter than the average for the two males.Comparison withM. f. longicaudaandM. f. nevadensisreveals that the tympanic bullae average more nearly flat and that the skull is smaller.
Type.—Male, adult, skull and skin; no. 186451, U. S. Nat. Mus. (formerly 4485/5120, collection of Dr. C. Hart Merriam); Custer, South Dakota; obtained by Vernon Bailey; original no. 90.
The skull is complete and unbroken. The upper incisors are missing. All the other teeth are present although the premolars, and especially the canines, are much worn, possibly as the result of the animal's efforts to free itself from a trap. The skin is fairly well made, in a good state of preservation, and entire.
Range.—Canadian, Transition and Upper Sonoran life-zones of the Black Hills of South Dakota and adjacent semi-bad-land territory of Wyoming and Nebraska southward to Mitchell, Scottsbluff County. See figure29on page221.
Characters for ready recognition.—Differs fromM. f. longicaudain smaller size, adult males having a total length of less than 400, hind foot less than 45, basilar length less than 43.5, and in adult females total length less than 375, and basilar length less than 40; fromM. f. nevadensisin near Clay Color rather than near (14ntol) Brussels Brown of upper parts in summer.
Description.—Size.—Male: External measurements of the type specimen are: Total length, 372; length of tail, 137; length of hind foot, 44. Tail is 58 per cent as long as head and body. Length of hind foot more than basal length.
Female: No external measurements for typical adults are available. No. M1 #41 from Mitchell, Scottsbluff Co., Nebraska, an adult female which is an intergrade with the largerM. f. longicauda, measures as follows: Total length, 367; length of tail, 120; length of hind foot, 41.
Externals.—Longest facial vibrissae dark brown or white 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) as shown in figure20.
Color.—Winter pelage unknown; probably white except, of course, tip of tail. Summer pelage as described inMustela frenata longicaudaexcept that: Least width of color of underparts averaging, in 3 males from Black Hills, 54 (38-62) per cent of greatest width of color of upper parts. Black tip of tail averaging 43 (40-45) mm. long. Thus, averaging approximately same length as hind foot and in type specimen amounting to 33 per cent of length of tail-vertebrae.
Skull and teeth.—Male (based on the type and no. 7440 Amer. Mus. Nat. Hist., from Hill City, S. Dak.): See measurements and plates18-20. As described inMustela frenata longicaudaexcept that: Weight, 3.1 (3.0-3.2) grams; basilar length, 41.0 (40.9-41.0); mastoid breadth not less than postpalatal length; breadth of rostrum more than length of P4; anterior margin of tympanic bulla as far posterior to foramen ovale as width of 4 to 5 upper incisors; height of tympanic bulla more or less than distance from its anterior margin to foramen ovale.
Female (based on no. 7441, American Mus. Nat. Hist., from Black Hills, S. Dak.): See measurements and plates31-33. As described inMustela frenata longicaudaexcept that: Weight, 2.0 grams; basilar length 37.6. The skull of the female is 35 per cent lighter than the average for the two males.
Comparison withM. f. longicaudaandM. f. nevadensisreveals that the tympanic bullae average more nearly flat and that the skull is smaller.
Remarks.—Animals of this subspecies were described and named by Merriam in 1896 as a distinct species on the basis of two or possibly three specimens from the Black Hills of South Dakota and the name seems never to have been applied to specimens from other regions. Vernon Bailey obtained only the one specimen, the type, on his trip in 1888, but two more were obtained for the American Museum of Natural History by Walter Granger in 1894.
Mustela frenata allenicombines the light coloration ofM. f. longicaudawith the small size ofM. f. nevadensis. Indeed, the size may average less than that ofnevadensis.M. f. alleniseems to reach its extreme of small size in the Black Hills of South Dakota. Specimens from Mitchell, Scottsbluff County, Nebraska, here referred to alleni are of larger size and in this respect are intermediate between the subspeciesalleniandlongicauda. Of the two specimens available from Chadron, Nebraska, and here referred to aslongicauda, the female, M1 #6, is almost exactly intermediate in size betweenalleniandlongicauda, whereas the male, M1 #11, is as large as the average-sizedlongicauda.
None of the nine skulls (5 adults) shows malformation resulting from the infestation of the frontal sinuses with parasites.
Specimens examined.—Total number, 10, as follows.Wyoming.Crook County: Sundance, 1[91].South Dakota.Pennington County: Hill City, 1[2]; 20 mi. N Elk Mt, 1[91].Countyin question: Black Hills, 1[2].Custer County: Custer, 2 (1[91], 1[2]).Nebraska.Scottsbluff County: Mitchell, 4[35].
Specimens examined.—Total number, 10, as follows.
Wyoming.Crook County: Sundance, 1[91].
South Dakota.Pennington County: Hill City, 1[2]; 20 mi. N Elk Mt, 1[91].Countyin question: Black Hills, 1[2].Custer County: Custer, 2 (1[91], 1[2]).
Nebraska.Scottsbluff County: Mitchell, 4[35].
Long-tailed Weasel
Plates19,20,21,31,32and33
Putorius arizonensisMearns, Bull. Amer. Mus. Nat. Hist., 3:234, June, 1891; Merriam, N. Amer. Fauna, 11:22, fig. 12, June 30, 1896.Mustela arizonensis, Miller, U. S. Nat. Mus. Bull., 79:99, December 31, 1912.Mustela frenata arizonensis, Hall, Carnegie Instit. Washington Publ. 473:106, November 20, 1936.
Putorius arizonensisMearns, Bull. Amer. Mus. Nat. Hist., 3:234, June, 1891; Merriam, N. Amer. Fauna, 11:22, fig. 12, June 30, 1896.
Mustela arizonensis, Miller, U. S. Nat. Mus. Bull., 79:99, December 31, 1912.
Mustela frenata arizonensis, Hall, Carnegie Instit. Washington Publ. 473:106, November 20, 1936.
Type.—Female, adult, skull and skin; no. 2490/1886, Amer. Mus. Nat. Hist.; San Francisco Forest [then (1886?), Yavapai County], Arizona; June 20, 1886; obtained by Edgar A. Mearns.The skull (plates31-33) is complete and unbroken save for a small puncture in the right squamosal. The incisors above and below and M2and P2on each side are missing. Four canines are preserved separately. Otherwise the teeth are in place. The skin has been taken down from a mount. Some hair has been lost from in front of the ears. Seven mammae are evident and show the animal to have been nursing young. The slightly faded color was mentioned by Mearns in the original description. He says (1891:234): "The memorandum of the colors was made before skinning, the specimen having been subsequently preserved in a solution of alum and salt, which extracted much of the coloring matter."Range.—Transition to Hudsonian life-zones of Arizona and extreme western New Mexico, along the Colorado River, and south of the Little Colorado River, from San Francisco Mountain region along Mogollon Plateau to extreme western New Mexico. See figure 29 on page221.Characters for ready recognition.—Differs fromM. f. neomexicanaby near (14n) Brussels Brown rather than Buckthorn Brown color of upper parts, in absence rather than presence of white frontal spot continuous with color of underparts, in basilar length of less than 44 in males and 39.3 in females; fromM. f. nevadensisin that total length averages less than 375 in males and 330 in females, basilar length averaging less than 41 in males and less than 36.7 in females.Description.—Size.—Male: No. 24679/32071, from Springerville, and no. 248993 from the Kaibab Plateau, measure respectively, as follows: Total length, 363, 367; length of tail, 140, 143; length of hind foot, 41.5, 41.0. Tail is 63, and 64 per cent as long as head and body. These males, the only specimens of that sex of which external measurements are available, probably are grading towardnevadensisand therefore are nontypical.Female: Three specimens, one young from Little Spring, a subadult from Deadmans Flat and the type specimen, measure respectively as follows: Total length, 323, 296, 302; length of tail, 110, 101, 109; length of hind foot, 38, 33, 36. These average, 307, 107, 36. Tail averages 53 per cent as long as head and body.Differences in external measurements of the two sexes are: Total length, 56; length of tail, 39; hind foot, 5.5.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) about as shown in figure19.Color.—Winter pelage unknown. Summer pelage with upper parts near (14 n) Brussels Brown or tone 2 of Raw Umber of Oberthür and Dauthenay, Pl. 301, darker on top of head from nose to line connecting posterior margins of ears. Tip of tail always black. Chin and upper lips white. Remainder of underparts Buff Yellow to Straw Yellow and rarely Ochraceous Buff. Color of underparts extends distally on posterior sides of forelegs over toes onto antipalmar faces of feet and wrists, on medial sides of hind legs to ankles and over antiplantar faces of toes, medial third of tarsus, and over proximal fifth to fourth of ventral side of tail. Least width of color of underparts averaging, in 8 specimens, 44 (29-54) per cent of greatest width of color of upper parts. Black tip of tail, in four females averaging 35 (33-38) mm. long. Thus, averaging shorter than hind foot and 32 per cent of length of tail-vertebrae. Three of the eight specimens before me (no. 242671 from 25 mi. SE Flagstaff, not available at time of this accounting) have the dark spot near the angle of the mouth faintly indicated, whereas the other five lack the spots. The color is as inM. f. nevadensis.Skull and teeth.—Male (based on 55211, 65231, and 248993; see page422): See measurements and plates19-21; weight 2.7 and 3.1 grams; basilar length, 40.4; 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 more or less than distance between foramen opticum and anterior margin of tympanic bulla; breadth of rostrum less than length of tympanic bulla; least width of palate more or less than medial length of P4; anterior margin of tympanic bulla as far posterior to foramen ovale as width of 3-1/2 (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-premolar tooth-row and longer or shorter than rostrum; anterior margin of masseteric fossa below talonid of m1.Female (based on the type specimen): See measurements and plates31-33; weight, 1.6 grams; basilar length, 35.5; zygomatic breadth less than distance between condylar foramen and M1 and more than distance between anterior palatine foramen and anterior margin of tympanic bulla (nearly equal in each instance); postorbital breadth less than length of upper premolars and greater (7.1-8.4) than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; least width of palate equal to inside length of P4; tympanic bulla as far posterior to foramen ovale as width of 3 (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-premolar tooth-row and greater than length of rostrum.The skull of the female averages 41 per cent lighter than that of the male.
Type.—Female, adult, skull and skin; no. 2490/1886, Amer. Mus. Nat. Hist.; San Francisco Forest [then (1886?), Yavapai County], Arizona; June 20, 1886; obtained by Edgar A. Mearns.
The skull (plates31-33) is complete and unbroken save for a small puncture in the right squamosal. The incisors above and below and M2and P2on each side are missing. Four canines are preserved separately. Otherwise the teeth are in place. The skin has been taken down from a mount. Some hair has been lost from in front of the ears. Seven mammae are evident and show the animal to have been nursing young. The slightly faded color was mentioned by Mearns in the original description. He says (1891:234): "The memorandum of the colors was made before skinning, the specimen having been subsequently preserved in a solution of alum and salt, which extracted much of the coloring matter."
Range.—Transition to Hudsonian life-zones of Arizona and extreme western New Mexico, along the Colorado River, and south of the Little Colorado River, from San Francisco Mountain region along Mogollon Plateau to extreme western New Mexico. See figure 29 on page221.
Characters for ready recognition.—Differs fromM. f. neomexicanaby near (14n) Brussels Brown rather than Buckthorn Brown color of upper parts, in absence rather than presence of white frontal spot continuous with color of underparts, in basilar length of less than 44 in males and 39.3 in females; fromM. f. nevadensisin that total length averages less than 375 in males and 330 in females, basilar length averaging less than 41 in males and less than 36.7 in females.
Description.—Size.—Male: No. 24679/32071, from Springerville, and no. 248993 from the Kaibab Plateau, measure respectively, as follows: Total length, 363, 367; length of tail, 140, 143; length of hind foot, 41.5, 41.0. Tail is 63, and 64 per cent as long as head and body. These males, the only specimens of that sex of which external measurements are available, probably are grading towardnevadensisand therefore are nontypical.
Female: Three specimens, one young from Little Spring, a subadult from Deadmans Flat and the type specimen, measure respectively as follows: Total length, 323, 296, 302; length of tail, 110, 101, 109; length of hind foot, 38, 33, 36. These average, 307, 107, 36. Tail averages 53 per cent as long as head and body.
Differences in external measurements of the two sexes are: Total length, 56; length of tail, 39; hind foot, 5.5.
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) about as shown in figure19.
Color.—Winter pelage unknown. Summer pelage with upper parts near (14 n) Brussels Brown or tone 2 of Raw Umber of Oberthür and Dauthenay, Pl. 301, darker on top of head from nose to line connecting posterior margins of ears. Tip of tail always black. Chin and upper lips white. Remainder of underparts Buff Yellow to Straw Yellow and rarely Ochraceous Buff. Color of underparts extends distally on posterior sides of forelegs over toes onto antipalmar faces of feet and wrists, on medial sides of hind legs to ankles and over antiplantar faces of toes, medial third of tarsus, and over proximal fifth to fourth of ventral side of tail. Least width of color of underparts averaging, in 8 specimens, 44 (29-54) per cent of greatest width of color of upper parts. Black tip of tail, in four females averaging 35 (33-38) mm. long. Thus, averaging shorter than hind foot and 32 per cent of length of tail-vertebrae. Three of the eight specimens before me (no. 242671 from 25 mi. SE Flagstaff, not available at time of this accounting) have the dark spot near the angle of the mouth faintly indicated, whereas the other five lack the spots. The color is as inM. f. nevadensis.
Skull and teeth.—Male (based on 55211, 65231, and 248993; see page422): See measurements and plates19-21; weight 2.7 and 3.1 grams; basilar length, 40.4; 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 more or less than distance between foramen opticum and anterior margin of tympanic bulla; breadth of rostrum less than length of tympanic bulla; least width of palate more or less than medial length of P4; anterior margin of tympanic bulla as far posterior to foramen ovale as width of 3-1/2 (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-premolar tooth-row and longer or shorter than rostrum; anterior margin of masseteric fossa below talonid of m1.
Female (based on the type specimen): See measurements and plates31-33; weight, 1.6 grams; basilar length, 35.5; zygomatic breadth less than distance between condylar foramen and M1 and more than distance between anterior palatine foramen and anterior margin of tympanic bulla (nearly equal in each instance); postorbital breadth less than length of upper premolars and greater (7.1-8.4) than width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; least width of palate equal to inside length of P4; tympanic bulla as far posterior to foramen ovale as width of 3 (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-premolar tooth-row and greater than length of rostrum.
The skull of the female averages 41 per cent lighter than that of the male.
Compared with the skull ofM. f. nevadensis, that ofarizonensisis smaller, less heavily ridged and has more inflated tympanic bullae and a relatively greater mastoid breadth. Comparison with the skull ofM. f. neomexicanais made in the account of that subspecies.
Remarks.—In 1891 Mearns (234-235) named this weasel as a full species on the basis of two individuals taken by him in 1886 and 1887. Since that time only a few additional specimens have been preserved. Only four are adults. Although this material does not permit of a definition of the subspecies as precise as could be wished, still, it clearly shows that the animals from the plateau region of Arizona are recognizably different from those farther north in the Sierra Nevada of California and those of the Rocky Mountains and Great Basin region northward to the Canadian border. These more northern animals have gone by Mearns' name,arizonensis, since the date of its proposal until 1939 when the namenevadensiswas proposed.
The smaller size, especially of the skull, and the greater inflation of the tympanic bullae are the outstanding characters which distinguisharizonensisfrom the similarly markednevadensis. The bullae are relatively much inflated throughout but especially so on the posteromedial parts.
Although the three adult males and two subadult females available of this subspecies are smaller in most parts measured than any of the scores ofnevadensisof similar age that have been measured, overlap in size probably will be found as additional specimens ofarizonensisbecome available. A young female, no. 18513, coll. D. R. Dickey, from Little Spring, does have certain cranial measurements as large as are found in the minimum-sizednevadensisfrom farther north.
Intergradation with the two subspecies whose geographic ranges adjoin that ofarizonensisis indicated by specimens at hand. One of these is the adult male from 25 miles southeast of Flagstaff, which shows decided approach toneomexicana, in color and in possessing white facial markings less well developed than inneomexicana. Even better developed white facial markings, with intervening blackish coloration, are displayed by no. 148271, U. S. Nat. Mus., from 8500 feet altitude on Willow Creek, New Mexico. This subadult female shows approach toneomexicanaalso in larger size of the skull and entire animal. The great inflation of the posterior part of each of its bullae and the dark color of the upper parts are characters ofarizonensis. The color of the underparts stops at the ankles leaving the hind feet dark colored, in which respect the specimen is unlike eitherneomexicanaorarizonensis. If additional specimens showing the same characters as this one be found at other nearby localities they probably should be given recognition as a separate subspecies. For the present it seems best to regard the specimen merely as an intergrade. Although it might, with almost equal propriety, be referred to eitherneomexicanaorarizonensis, the specimen is here placed with the latter. The subadult male from Springerville, Arizona, is of larger size than the topotypical male ofarizonensisand in this respect shows slight approach tonevadensis. The narrower mastoidal breadth and slightly less inflated tympanic bullae of the male from the Kaibab Plateau may reflect merely individual variation or may represent intergradation in these features withnevadensis.
The statement made by Merriam (1896:22) that, "The type specimen . . . is an immature female and is of unusually small size. A male obtained by him [Mearns] near the same place is of the normal size, as is another male in the Department collection from Springerville, Ariz., collected by E. W. Nelson," needs correction. The female is not immature. The specimen obtained by Mearns near the same place probably refers to Amer. Mus. No. 2489, from Quaking Asp Settlement, which lacks both the skull and external measurements. As stuffed it is of small size for a male. The male from Springerville, as shown by the external and cranial measurements, is not of normal (i. e.average) size, but is smaller than the average for the other populations of similarly colored weasels referred to by Merriam (op. cit.) asarizonensisbut here described under the namenevadensis.
None of the skulls shows signs of infestation of the frontal sinuses by parasites.
Specimens examined.—Total number, 17, arranged alphabetically by states and from north to south by counties in each state. Unless otherwise indicated specimens are in the collection of the United States National Museum.Arizona.Coconino County: VT Park, Kaibab Plateau, 1; Deadman Flat, 6400 ft., 1[74]; Little Spring, 1[59]; Government Prairie, near Parks, 1[74];Coconino? County: San Francisco Forest (Yavapai Co., in 1886), 1[2]; 25 mi. SE Flagstaff, 1; Quaking Asp Settlement, 1[2].Apache County: Springerville, 1; North Fork White River, White Mts., 8200 ft., 4[87]; head San Francisco River, Judd Ranch, Alpine, 1[74]; 2 mi. SE Big Lake Knoll, 8700 ft., 24 mi. S Springerville, 1[74].Greenlee County: S end Blue Range, 9000 ft., Prieto Plateau, 1; Beaver Creek, 7000 ft., 1[74].New Mexico.Grant County: Mogollon Mts., Willow Creek, 8500 ft., 1.
Specimens examined.—Total number, 17, arranged alphabetically by states and from north to south by counties in each state. Unless otherwise indicated specimens are in the collection of the United States National Museum.
Arizona.Coconino County: VT Park, Kaibab Plateau, 1; Deadman Flat, 6400 ft., 1[74]; Little Spring, 1[59]; Government Prairie, near Parks, 1[74];Coconino? County: San Francisco Forest (Yavapai Co., in 1886), 1[2]; 25 mi. SE Flagstaff, 1; Quaking Asp Settlement, 1[2].Apache County: Springerville, 1; North Fork White River, White Mts., 8200 ft., 4[87]; head San Francisco River, Judd Ranch, Alpine, 1[74]; 2 mi. SE Big Lake Knoll, 8700 ft., 24 mi. S Springerville, 1[74].Greenlee County: S end Blue Range, 9000 ft., Prieto Plateau, 1; Beaver Creek, 7000 ft., 1[74].
New Mexico.Grant County: Mogollon Mts., Willow Creek, 8500 ft., 1.
Long-tailed Weasel
Plates19,20,21,33,34,35and39
Mustela frenata nevadensisHall, Carnegie Instit. Washington Publ. 473:91, November 20, 1936.Putorius longicauda, Coues, Fur-bearing animals, p. 136, 1877 (part); Merriam, N. Amer. Fauna, 5:83, July 30, 1891.Putorius (Gale) brasiliensis frenatus, Coues, Fur-bearing animals, p. 142, 1877 (part).Putorius arizonensis, Merriam, N. Amer. Fauna, 11:22, figs. 13, 14, June 30, 1896 (part); Stephens, Mammals of California, p. 247, 1906.Mustela arizonensis, Grinnell and Swarth, Univ. California Publ. Zoöl., 10:376, October 31, 1913; Whitlow and Hall, Univ. California Publ. Zoöl., 40:247, September 30, 1933.Mustela arizonensis arizonensis, Grinnell, Univ. California Publ. Zoöl., 40:102, September 26, 1933.Mustela frenata, Boyer, Journ. Mamm., 24:99, February 20, 1943.
Mustela frenata nevadensisHall, Carnegie Instit. Washington Publ. 473:91, November 20, 1936.
Putorius longicauda, Coues, Fur-bearing animals, p. 136, 1877 (part); Merriam, N. Amer. Fauna, 5:83, July 30, 1891.
Putorius (Gale) brasiliensis frenatus, Coues, Fur-bearing animals, p. 142, 1877 (part).
Putorius arizonensis, Merriam, N. Amer. Fauna, 11:22, figs. 13, 14, June 30, 1896 (part); Stephens, Mammals of California, p. 247, 1906.
Mustela arizonensis, Grinnell and Swarth, Univ. California Publ. Zoöl., 10:376, October 31, 1913; Whitlow and Hall, Univ. California Publ. Zoöl., 40:247, September 30, 1933.
Mustela arizonensis arizonensis, Grinnell, Univ. California Publ. Zoöl., 40:102, September 26, 1933.
Mustela frenata, Boyer, Journ. Mamm., 24:99, February 20, 1943.
Type.—Female, adult, skull and skin; no. 41053, Mus. Vert. Zoöl.; three miles east Baker, White Pine County, Nevada; May 30, 1929; obtained by E. R. Hall and W. C. Russell; original no. 2674, E. R. H.The skull (plates33-35) is complete and unbroken. The teeth all are present and entire. The skin is fairly well made. Eight mammae are evident and show the animal to have been nursing young.Range.—Altitudinally, 700 feet at Wenatchee, Washington, to the highest parts of the mountains of the western United States; Upper Sonoran Life-zone to Arctic Alpine Life-zone; southern British Columbia in the Cascades and territory west to Monashee Mountains, and Nelson, southward in the Cascades of northern Washington, over western Washington, Idaho, Utah, and Nevada to northeastern Arizona and northern New Mexico; westward from the eastern base of the Rocky Mountains in Colorado to the western base of the Sierra Nevada and Cascades of California and to the Cascades of southern Oregon. See figures29and30on pages 221 and 314.Characters for ready recognition.—Differs fromM. f. oribasusby smaller average size, see measurements; fromM. f. longicaudaby near (14ntol) Brussels Brown rather than near (h) Clay Color of the upper parts, and in males by a 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. alleniby near (14ntol) Brussels Brown rather than near (h) Clay Color of upper parts in summer; fromM. f. neomexicanaby near (14ntol) Brussels Brown rather than Buckthorn Brown color of upper parts, in absence of white frontal spot continuous with color of underparts, in basilar length of less than 46 in males and 40 in females; fromM. f. arizonensisby total length averaging more than 375 in males and 330 in females, basilar length averaging more than 41 in males and 36.7 in females; fromM. f. inyoensisby absence of white facial markings; fromM. f. pulchraby absence of light facial markings, near (14ntol) Brussels Brown rather than near (16j) Buckthorn Brown color of upper parts, and lesser size, hind foot less than 40 in females and basilar length averaging less than 46.0 in males; fromM. f. xanthogenysby absence of light facial markings and near (14ntol) Brussels Brown rather than Buckthorn Brown color of upper parts; fromM. f. mundaby absence of white facial markings, presence of color of underparts on ventral face of proximal third of tail, and hind foot of less than 50 in males; fromM. f. saturataby presence of light color of underparts on tail and ankle and in lesser average breadth across mastoid processes of skull (see measurements); fromM. f. oregonensisby absence of nasofrontal white patch, presence of light color of underparts on ventral face of tail, and shorter skull, which, relative to its length in males, is deeper through the braincase; fromM. f. washingtoniby presence of light color of underparts on ventral face of tail, by skull which in male relative to basilar length is shorter in the preorbital region and wider across the zygomata and mastoid processes, and in female has longer preorbital region and larger bullae (see measurements); fromM. f. altifrontalisby lighter colored upper parts which are tones 1 to 3 of Raw Umber, pl. 301, rather than tone 4 of Brownish Drab, pl. 302, of Oberthür and Dauthenay, by Buff-Yellow to Straw Yellow rather than near (14´ato 16´c) Ochraceous-Buff color of underparts, by least width of color of underparts amounting to more than 37 per cent of greatest width of color of upper parts, by presence of color of underparts on ventral side of tail and on hind leg over ankle, and by lesser depth of skull through frontal region; fromM. f. efferaby larger size, males averaging 12-1/2 per cent larger in external measurements, 8 per cent larger in linear measurements of skull, and 22 per cent heavier in weight of skull, total length averaging 400 rather than 360, basilar length averaging 43.6 rather than 40.5.Description.—Size.—Male: Twenty-one adults from the southern half of the Sierra Nevada of California yield average and extreme measurements as follows: Total length, 400 (356-428); length of tail, 150 (125-178); length of hind foot, 46.1 (42-50). Tail averages 60 per cent as long as head and body. Length of hind foot averaging more than basal length. Corresponding measurements of twelve adults from extreme southern and southwestern Colorado are as follows: 407 (355-431); 150 (133-170); 46.0 (42-49).Female: Ten adults from the Sierra Nevada of California yield average and extreme measurements as follows: Total length, 349 (336-362); length of tail, 127 (120-133); length of hind foot, 36.3 (32-39). Tail averages 57 per cent as long as head and body. Length of hind foot less than basal length. Corresponding measurements of ten adults from the Rocky Mountains of central Colorado are as follows: 347 (325-375); 123 (111-141); 40 (32-43).The average differences in external measurements of the two sexes, in the Sierras of California are: Total length, 51; length of tail, 23; length of hind foot, 9.8. Weight of 7 adult males from California is 267 (226-345) grams. Two adult females from there weigh 148 and 115 grams and 3 from White Pine County, Nevada, 134, 122 and 124, giving an average of 129 grams.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) about as shown in figure19.Color.—Upper parts, in summer, near (14ntol) Brussels Brown or tones 1 to 3 of Raw Umber of Oberthür and Dauthenay, pl. 301, darker on top of head from nose to line connecting posterior margins of ears. Chin and upper lips white. Remainder of underparts Buff-Yellow to Straw Yellow and sometimes Ochraceous-Buff especially in young, and in some adults from southern Colorado. In winter, all white, except tip of tail, or upper parts near (j) Snuff Brown or lighter than Brussels Brown with a smoked effect, and underparts white. Tip of tail at all times black. Color of underparts extends distally on posterior sides of forelegs over toes onto antipalmar faces of feet and wrists, on medial sides of hind legs to ankles, over antiplantar faces of toes, medial third of tarsus and usually over proximal tenth to three-fourths of ventral side of tail. Least width of color of underparts averaging, in a series of twenty males from the southern half of the Sierra Nevada of California, 59 (37-76) per cent of greatest width of color of upper parts. In seven males from southern Colorado corresponding percentages are 55 (37-71). Black tip of tail in series from Sierra Nevada averaging 50 (40-60) mm. long; thus longer than hind foot and averaging 33-1/3 per cent of length of tail-vertebrae.Skull and teeth.—Male (based on 25 adults, from Sierra Nevada of California): See measurements and plates19-21; weight, 3.7 (2.9-4.9) grams; basilar length, 43.6 (40.6-46.1); zygomatic breadth more than distance between condylar foramen and M1 (save in four instances) and more than distance between anterior palatine foramen and anterior margin of tympanic bulla (save in two specimens); mastoid breadth more (80 per cent of specimens) or less (20 per cent) than postpalatal length; 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; 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; least width of palate less than medial length of P4 (except in two specimens); anterior margin of tympanic bulla as far posterior to foramen ovale as width of 3 to 5 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 not carried farther forward than point directly below hypoconid of m1.Female (based on ten adults from Sierra Nevada of California): See measurements and plates33-35; weight, 2.2 (1.8-2.4) grams; basilar length, 38.2 (36.7-39.5); zygomatic breadth more (except in one specimen) than distance between condylar foramen and M1 and more (save in two specimens) than distance between anterior palatine foramen and anterior margin of tympanic bulla; postorbital breadth less than length of upper premolars and less than (except in one specimen) width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; least width of palate more or less than either outside or inside length of P4 but generally less than inside length; tympanic bulla as far posterior to foramen ovale as width of 3 to 5-1/2 upper incisors; height of tympanic bulla more or less (usually 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 more or less than length of rostrum.The skull of the female averages 41 per cent lighter than that of the average male.
Type.—Female, adult, skull and skin; no. 41053, Mus. Vert. Zoöl.; three miles east Baker, White Pine County, Nevada; May 30, 1929; obtained by E. R. Hall and W. C. Russell; original no. 2674, E. R. H.
The skull (plates33-35) is complete and unbroken. The teeth all are present and entire. The skin is fairly well made. Eight mammae are evident and show the animal to have been nursing young.
Range.—Altitudinally, 700 feet at Wenatchee, Washington, to the highest parts of the mountains of the western United States; Upper Sonoran Life-zone to Arctic Alpine Life-zone; southern British Columbia in the Cascades and territory west to Monashee Mountains, and Nelson, southward in the Cascades of northern Washington, over western Washington, Idaho, Utah, and Nevada to northeastern Arizona and northern New Mexico; westward from the eastern base of the Rocky Mountains in Colorado to the western base of the Sierra Nevada and Cascades of California and to the Cascades of southern Oregon. See figures29and30on pages 221 and 314.
Characters for ready recognition.—Differs fromM. f. oribasusby smaller average size, see measurements; fromM. f. longicaudaby near (14ntol) Brussels Brown rather than near (h) Clay Color of the upper parts, and in males by a 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. alleniby near (14ntol) Brussels Brown rather than near (h) Clay Color of upper parts in summer; fromM. f. neomexicanaby near (14ntol) Brussels Brown rather than Buckthorn Brown color of upper parts, in absence of white frontal spot continuous with color of underparts, in basilar length of less than 46 in males and 40 in females; fromM. f. arizonensisby total length averaging more than 375 in males and 330 in females, basilar length averaging more than 41 in males and 36.7 in females; fromM. f. inyoensisby absence of white facial markings; fromM. f. pulchraby absence of light facial markings, near (14ntol) Brussels Brown rather than near (16j) Buckthorn Brown color of upper parts, and lesser size, hind foot less than 40 in females and basilar length averaging less than 46.0 in males; fromM. f. xanthogenysby absence of light facial markings and near (14ntol) Brussels Brown rather than Buckthorn Brown color of upper parts; fromM. f. mundaby absence of white facial markings, presence of color of underparts on ventral face of proximal third of tail, and hind foot of less than 50 in males; fromM. f. saturataby presence of light color of underparts on tail and ankle and in lesser average breadth across mastoid processes of skull (see measurements); fromM. f. oregonensisby absence of nasofrontal white patch, presence of light color of underparts on ventral face of tail, and shorter skull, which, relative to its length in males, is deeper through the braincase; fromM. f. washingtoniby presence of light color of underparts on ventral face of tail, by skull which in male relative to basilar length is shorter in the preorbital region and wider across the zygomata and mastoid processes, and in female has longer preorbital region and larger bullae (see measurements); fromM. f. altifrontalisby lighter colored upper parts which are tones 1 to 3 of Raw Umber, pl. 301, rather than tone 4 of Brownish Drab, pl. 302, of Oberthür and Dauthenay, by Buff-Yellow to Straw Yellow rather than near (14´ato 16´c) Ochraceous-Buff color of underparts, by least width of color of underparts amounting to more than 37 per cent of greatest width of color of upper parts, by presence of color of underparts on ventral side of tail and on hind leg over ankle, and by lesser depth of skull through frontal region; fromM. f. efferaby larger size, males averaging 12-1/2 per cent larger in external measurements, 8 per cent larger in linear measurements of skull, and 22 per cent heavier in weight of skull, total length averaging 400 rather than 360, basilar length averaging 43.6 rather than 40.5.
Description.—Size.—Male: Twenty-one adults from the southern half of the Sierra Nevada of California yield average and extreme measurements as follows: Total length, 400 (356-428); length of tail, 150 (125-178); length of hind foot, 46.1 (42-50). Tail averages 60 per cent as long as head and body. Length of hind foot averaging more than basal length. Corresponding measurements of twelve adults from extreme southern and southwestern Colorado are as follows: 407 (355-431); 150 (133-170); 46.0 (42-49).
Female: Ten adults from the Sierra Nevada of California yield average and extreme measurements as follows: Total length, 349 (336-362); length of tail, 127 (120-133); length of hind foot, 36.3 (32-39). Tail averages 57 per cent as long as head and body. Length of hind foot less than basal length. Corresponding measurements of ten adults from the Rocky Mountains of central Colorado are as follows: 347 (325-375); 123 (111-141); 40 (32-43).
The average differences in external measurements of the two sexes, in the Sierras of California are: Total length, 51; length of tail, 23; length of hind foot, 9.8. Weight of 7 adult males from California is 267 (226-345) grams. Two adult females from there weigh 148 and 115 grams and 3 from White Pine County, Nevada, 134, 122 and 124, giving an average of 129 grams.
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) about as shown in figure19.
Color.—Upper parts, in summer, near (14ntol) Brussels Brown or tones 1 to 3 of Raw Umber of Oberthür and Dauthenay, pl. 301, darker on top of head from nose to line connecting posterior margins of ears. Chin and upper lips white. Remainder of underparts Buff-Yellow to Straw Yellow and sometimes Ochraceous-Buff especially in young, and in some adults from southern Colorado. In winter, all white, except tip of tail, or upper parts near (j) Snuff Brown or lighter than Brussels Brown with a smoked effect, and underparts white. Tip of tail at all times black. Color of underparts extends distally on posterior sides of forelegs over toes onto antipalmar faces of feet and wrists, on medial sides of hind legs to ankles, over antiplantar faces of toes, medial third of tarsus and usually over proximal tenth to three-fourths of ventral side of tail. Least width of color of underparts averaging, in a series of twenty males from the southern half of the Sierra Nevada of California, 59 (37-76) per cent of greatest width of color of upper parts. In seven males from southern Colorado corresponding percentages are 55 (37-71). Black tip of tail in series from Sierra Nevada averaging 50 (40-60) mm. long; thus longer than hind foot and averaging 33-1/3 per cent of length of tail-vertebrae.
Skull and teeth.—Male (based on 25 adults, from Sierra Nevada of California): See measurements and plates19-21; weight, 3.7 (2.9-4.9) grams; basilar length, 43.6 (40.6-46.1); zygomatic breadth more than distance between condylar foramen and M1 (save in four instances) and more than distance between anterior palatine foramen and anterior margin of tympanic bulla (save in two specimens); mastoid breadth more (80 per cent of specimens) or less (20 per cent) than postpalatal length; 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; 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; least width of palate less than medial length of P4 (except in two specimens); anterior margin of tympanic bulla as far posterior to foramen ovale as width of 3 to 5 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 not carried farther forward than point directly below hypoconid of m1.
Female (based on ten adults from Sierra Nevada of California): See measurements and plates33-35; weight, 2.2 (1.8-2.4) grams; basilar length, 38.2 (36.7-39.5); zygomatic breadth more (except in one specimen) than distance between condylar foramen and M1 and more (save in two specimens) than distance between anterior palatine foramen and anterior margin of tympanic bulla; postorbital breadth less than length of upper premolars and less than (except in one specimen) width of basioccipital measured from medial margin of one foramen lacerum posterior to its opposite; least width of palate more or less than either outside or inside length of P4 but generally less than inside length; tympanic bulla as far posterior to foramen ovale as width of 3 to 5-1/2 upper incisors; height of tympanic bulla more or less (usually 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 more or less than length of rostrum.
The skull of the female averages 41 per cent lighter than that of the average male.
Compared with the skull ofM. f. longicauda, that of both sexes averages smaller in every measurement taken. Males ofnevadensis, on the average, relative to the basilar length, are narrower in the interorbital region and across the zygomata but have the orbitonasal length greater. Stated in another way, the rostrum oflongicaudaappears to be shorter and broader and the zygomata are more expanded. Females ofnevadensis, on the average, relative to the basilar length are narrower across the mastoid processes and zygomata and have the braincase deeper at the anterior margin of the basioccipital. Also innevadensisthe mastoid processes do not project so far laterally beyond the braincase, the lambdoidal crest and postorbital processes are less well developed and except in the interparietal region, the temporal ridges hardly meet and they form a sagittal furrow rather than a low sagittal crest which characterizes adult females oflongicauda. Each of these differences separating the females oflongicaudafrom those ofnevadensisare of the same nature, although not necessarily of the same degree, as those which appear inlongicaudawith increasing age. The differences mentioned above are readily appreciable when series of specimens are compared. However, none of the differences is of great degree, and most parts of the skulls of the two subspecies are of similar relative proportions. Even so, there is but little overlap in actual size. Comparisons with the skulls ofM. f. oribasus,alleni,neomexicana,arizonensis,inyoensis,pulchra,xanthogenys,munda,saturata,oregonensis,washingtoni,altifrontalis, andefferaare made in the accounts of those subspecies.
Remarks.—The populations to which the namenevadensisat present is assigned have gone by the namearizonensissince Mearns proposed this name in 1891. Before that time Coues (1877:141) had included individuals of this race under the namePutorius longicauda.