Type.—Male, adult, skull and skin; no. 76646, U. S. Nat. Mus., Biol. Surv. Coll.; Mount Vernon, Skagit Valley, Skagit County, Washington; February 29, 1896; obtained by D. R. Luckey, original no. 3.The skull is unbroken and the teeth all are present and entire. The skin, in brown winter pelage, is stuffed and in good condition.Range.—Western Washington along eastern side of Puget Sound, western Oregon from the Cascades to the coast, and northwestern California south in the humid coastal district nearly to the Golden Gate. See figures25,27on pages 95, 149.Characters for ready recognition.—Differs fromM. e. anguinae, in male, by sagittal crest present and hind foot ordinarily less than 33.5, in female by hind foot less than 27.5, basilar length less than 30.2; fromM. e. fallenda, in both sexes, by black tip of tail less than half of length of tail-vertebrae, in males hind foot less than 33.7, tympanic bulla about same length as, instead of longer than, upper tooth-rows; weight of skull less than 1-1/4 grams, in female weight of skull less than 0.7 grams, length of lateral side of P4 less than 4 mm.; fromM. e. olympica, by larger size, in males hind foot more than 33.0, basilar length ordinarily more than 32.5, in females by hind foot ordinarily longer than 24, by breadth of rostrum more than 8.6, depth of braincase at posterior border of upper molars more than 7.6; fromM. e. gulosaandmuricus, in both sexes, by upper lips brown (not white), light color of underparts extending down hind leg no farther than knee, depth of skull at posterior border of upper molars more than 7.7 in females and ordinarily more than 9.6 in males, further frommuricusby tail more than 62 in males and more than 49 in females; fromM. e. invictaby upper lips white (not brown), in males hind foot more than 36 and basilar length more than 35, in females hind foot more than 29.5 and basilar length more than 30.5.Description.—Size.—Male: Twelve adults from Blaine and Tillamook, Oregon, yield average and extreme measurements as follows: Total length, 255 (245-275); length of tail, 72 (64-80); length of hind foot, 31.5 (30.0-33.5).Female: Seven adults from Blaine and Tillamook, Oregon, yield average and extreme measurements as follows: Total length, 214 (193-230); length of tail, 55 (50-63); length of hind foot, 25 (24-27).Color.—Winter and summer pelages indistinguishable; upper parts uniform and ranging from Raw Umber to slightly darker (16n), and about tones 1 to 3 of Dark Chocolate of Oberthür and Dauthenay, pl. 342; underparts white, in summer rarely with a faint buffy suffusion in pectoral region; color of underparts extends from chin, and often lower lips, posteriorly to inguinal region, distally on posterior sides of forelegs onto antipalmar faces of toes (sometimes interrupted at and above wrist) and on medial sides of hind legs hardly to knee. Least width of color of underparts averaging, in twelve adults from Blaine and Tillamook, 10 (0-47) per cent of greatest width of color of upper parts. Black tip of tail, in same series, averaging 28 (24-33) mm. which is 40 (34-47) per cent of length of tail-vertebrae.Skull.—Male (based on 12 adults): See measurements and plates5-7. As described inMustela erminea richardsoniiexcept that: Weight, 1.1 (1.0-1.2) grams; basilar length, 33.2 (32.5-33.8); length of tooth-rows more or less than (about same as) length of tympanic bulla.Female (based on 7 adults): See measurements and plates12-14. As described inMustela erminea richardsoniiexcept that: Weight, 0.64 (0.60-0.67) grams; basilar length, 28.5 (27.6-29.5); breadth of rostrum more than 30 per cent of basilar length.
Type.—Male, adult, skull and skin; no. 76646, U. S. Nat. Mus., Biol. Surv. Coll.; Mount Vernon, Skagit Valley, Skagit County, Washington; February 29, 1896; obtained by D. R. Luckey, original no. 3.
The skull is unbroken and the teeth all are present and entire. The skin, in brown winter pelage, is stuffed and in good condition.
Range.—Western Washington along eastern side of Puget Sound, western Oregon from the Cascades to the coast, and northwestern California south in the humid coastal district nearly to the Golden Gate. See figures25,27on pages 95, 149.
Characters for ready recognition.—Differs fromM. e. anguinae, in male, by sagittal crest present and hind foot ordinarily less than 33.5, in female by hind foot less than 27.5, basilar length less than 30.2; fromM. e. fallenda, in both sexes, by black tip of tail less than half of length of tail-vertebrae, in males hind foot less than 33.7, tympanic bulla about same length as, instead of longer than, upper tooth-rows; weight of skull less than 1-1/4 grams, in female weight of skull less than 0.7 grams, length of lateral side of P4 less than 4 mm.; fromM. e. olympica, by larger size, in males hind foot more than 33.0, basilar length ordinarily more than 32.5, in females by hind foot ordinarily longer than 24, by breadth of rostrum more than 8.6, depth of braincase at posterior border of upper molars more than 7.6; fromM. e. gulosaandmuricus, in both sexes, by upper lips brown (not white), light color of underparts extending down hind leg no farther than knee, depth of skull at posterior border of upper molars more than 7.7 in females and ordinarily more than 9.6 in males, further frommuricusby tail more than 62 in males and more than 49 in females; fromM. e. invictaby upper lips white (not brown), in males hind foot more than 36 and basilar length more than 35, in females hind foot more than 29.5 and basilar length more than 30.5.
Description.—Size.—Male: Twelve adults from Blaine and Tillamook, Oregon, yield average and extreme measurements as follows: Total length, 255 (245-275); length of tail, 72 (64-80); length of hind foot, 31.5 (30.0-33.5).
Female: Seven adults from Blaine and Tillamook, Oregon, yield average and extreme measurements as follows: Total length, 214 (193-230); length of tail, 55 (50-63); length of hind foot, 25 (24-27).
Color.—Winter and summer pelages indistinguishable; upper parts uniform and ranging from Raw Umber to slightly darker (16n), and about tones 1 to 3 of Dark Chocolate of Oberthür and Dauthenay, pl. 342; underparts white, in summer rarely with a faint buffy suffusion in pectoral region; color of underparts extends from chin, and often lower lips, posteriorly to inguinal region, distally on posterior sides of forelegs onto antipalmar faces of toes (sometimes interrupted at and above wrist) and on medial sides of hind legs hardly to knee. Least width of color of underparts averaging, in twelve adults from Blaine and Tillamook, 10 (0-47) per cent of greatest width of color of upper parts. Black tip of tail, in same series, averaging 28 (24-33) mm. which is 40 (34-47) per cent of length of tail-vertebrae.
Skull.—Male (based on 12 adults): See measurements and plates5-7. As described inMustela erminea richardsoniiexcept that: Weight, 1.1 (1.0-1.2) grams; basilar length, 33.2 (32.5-33.8); length of tooth-rows more or less than (about same as) length of tympanic bulla.
Female (based on 7 adults): See measurements and plates12-14. As described inMustela erminea richardsoniiexcept that: Weight, 0.64 (0.60-0.67) grams; basilar length, 28.5 (27.6-29.5); breadth of rostrum more than 30 per cent of basilar length.
Comparison withanguinae,fallenda,olympica,gulosaandmuricusis made in accounts of those subspecies.
Remarks.—This weasel is rare in collections and the best material of it was obtained by Alex Walker in Tillamook County, Oregon, where he resides. The almost ideal series of 30 specimens showed the range of secondary sexual, age, and individual variation expectable in the small ermines of the Pacific Coast of the United States and was the means of allowing satisfactory decision on questions of classification in the related subspecies in which individuals are of comparable size.
Intergradation with each of the geographically adjoining subspecies,olympica,fallenda,invicta,gulosaandmuricusis shown by specimens examined. With the last mentioned subspecies, intergradation is shown by two specimens from as far south as Siskiyou County, California, assigned tomuricus.
The application of the namestreatoriis difficult because it was based on a specimen from a place where two clines cross. The north-south cline is one of size which decreases to the south. The east-west cline is one of intensity of color, the westernmost (coastal) population being the most intensely colored. The type locality ofstreatoriis at the place where two lines perpendicular to one another, and representing the two clines, cross. This intersection is near the place where the ranges of several subspecies meet. The nomenclatural question is, to which one of 6 subspecies should the namestreatoriapply. Specimens from barely within the geographic boundaries of four of these subspecies so closely resemble topotypes ofstreatorithat a student with material at his disposal from only the area about Puget Sound naturally would apply the namestreatorito all of his specimens, and knowing even of the arrangement adopted in the present account the student will have difficulty in identifying his specimens according to it. Not only will the student find the arrangement difficult, but probably unsatisfactory if he thinks ofstreatorias being the kind of animal represented by topotypes. I conceive of topotypes ofstreatorias being nontypical of the subspecies; they are intergrades withfallenda. My aim was initially to work out the geographic ranges of subspecies and only subsequently to apply names, according to which type localities fell within the previously determined geographic ranges. By this procedure no greater weight was given to a holotype and to topotypes than to specimens from any other locality.
Of the 40 specimens seen in winter pelage, only one is white. It is from Darrington in the Cascade Mountains of Washington. The 39 others are brown and I doubt that the white pelage ever occurs in the low coastal territory included within the geographic range ofstreatori. This subspecies resemblesanguinaeandolympicain the great extension of area of the dark-colored upper parts at the expense of the area of the light-colored underparts. The usual arrangement is one where the brown of the two sides nearly meets on the midventral line leaving a sizable, inguinal area of light color connected by a thin line to the sizable area of light color on the pectoral region. The light color of the pectoral area ordinarily is continuous with the light-colored area of the throat and chin but the dark color of the upper parts extends around in front of each foreleg. These extensions of dark color meet on the chest in only 2 of the 56 specimens examined in this regard. Across the abdomen the dark color is continuous in 4 of the 56 specimens. The lower lips are brown instead of white in only 3 individuals and in 2 of these the lip of one side is brown and its opposite is white. The variation in color-pattern is less than inanguinaeor than infallenda.
Specimens examined.—Total number, 63, arranged alphabetically by states, then by counties from north to south in each state. Unless otherwise indicated, specimens are in the U. S. National Museum.California.Humboldt County: 10 mi. NE Carlotta, 1[74].Mendocino County: Russian Gulch State Park, 1[74].Sonoma County: Mouth of Gualala River, 1[74].Oregon.Clatsop County: Astoria, 1.Tillamook County: Tillamook, 16 (14[14], 1[59]); Blaine, 12 (7[14], 2[59], 1[93], 2[76]).Washington County: Beaverton, 1[60]; Forest Grove, 1[36].Clackamas County: Oregon City, 1[46].Lincoln County: Newport, 1.Linn County: Sico, 1[46].Lane County: Vida Fish Hatchery, 2[101]; McKenzie Bridge, 1[101]; Mercer, 1[75].Klamath County: Deschutes River, 6 mi. E Crescent Lake, 1[101].Douglas County: Gardiner, 1[60].Curry County: Port Orford, 1; Gold Beach, 2[60].Washington.Skagit County: N end Whidby Island opposite Deception Pass, 1; Hamilton, 4; Mt. Vernon, 3.Snohomish County: Oso, 550 ft., 1; Darrington, 600 ft., 1.Pacific County: Wallicut River, 2 mi. E Ilwaco, 1[74].Wahkiakum County: 4 mi. E. Skamokawa, 3[74].Cowlitz County: 4 mi. E mouth Kalama River, 2[74]; 6 mi. E mouth Kalama River, 1[74].Skamania County: 15 mi. N Govt. Springs, 1300 ft., 1.
Specimens examined.—Total number, 63, arranged alphabetically by states, then by counties from north to south in each state. Unless otherwise indicated, specimens are in the U. S. National Museum.
California.Humboldt County: 10 mi. NE Carlotta, 1[74].Mendocino County: Russian Gulch State Park, 1[74].Sonoma County: Mouth of Gualala River, 1[74].
Oregon.Clatsop County: Astoria, 1.Tillamook County: Tillamook, 16 (14[14], 1[59]); Blaine, 12 (7[14], 2[59], 1[93], 2[76]).Washington County: Beaverton, 1[60]; Forest Grove, 1[36].Clackamas County: Oregon City, 1[46].Lincoln County: Newport, 1.Linn County: Sico, 1[46].Lane County: Vida Fish Hatchery, 2[101]; McKenzie Bridge, 1[101]; Mercer, 1[75].Klamath County: Deschutes River, 6 mi. E Crescent Lake, 1[101].Douglas County: Gardiner, 1[60].Curry County: Port Orford, 1; Gold Beach, 2[60].
Washington.Skagit County: N end Whidby Island opposite Deception Pass, 1; Hamilton, 4; Mt. Vernon, 3.Snohomish County: Oso, 550 ft., 1; Darrington, 600 ft., 1.Pacific County: Wallicut River, 2 mi. E Ilwaco, 1[74].Wahkiakum County: 4 mi. E. Skamokawa, 3[74].Cowlitz County: 4 mi. E mouth Kalama River, 2[74]; 6 mi. E mouth Kalama River, 1[74].Skamania County: 15 mi. N Govt. Springs, 1300 ft., 1.
Ermine
Plates5,6,7,12,13and14
Mustela erminea gulosaHall, Journ. Mamm., 26:84, February 27, 1945; Hall, Journ. Mamm., 26:181, July 19, 1945.Putorius streatoriMerriam, N. Amer. Fauna, 11:14, June 30, 1896.
Mustela erminea gulosaHall, Journ. Mamm., 26:84, February 27, 1945; Hall, Journ. Mamm., 26:181, July 19, 1945.
Putorius streatoriMerriam, N. Amer. Fauna, 11:14, June 30, 1896.
Type.—Male, subadult, skull and skin; no. 81998, U. S. Nat. Mus., Biol. Surv. Coll.; Trout Lake, Klickitat County, Washington; February 3, 1897; obtained by P. Schmid, original no. 147.The skin is in brown winter pelage, and appears to have been made up from a skin split along the midventral line from the anus to the forelegs. It probably was dried by a trapper, is well made, and lacks a patch of hair on the left flank but otherwise is in good condition. The skull lacks the central part of the left zygomatic arch and the posterior two-thirds of the right one. The right m2 is represented only by an abortive stump or the broken root, and i1 and i2 on each side are absent; otherwise, the teeth all are present and entire.Range.—Cascades of Washington from northeastern King County south to Mount Adams. See figures25,27on pages 95, 149.Characters for ready recognition.—Differs fromM. e. invictaandfallenda, in both sexes, by anterior margin of tympanic bulla flush with squamosal rather than projecting below floor of braincase (difference slight in females), in males hind foot less than 33.5, weight of skull less than 1-1/4 grams, basilar length less than 33.9, in females by total length less than 222, hind foot shorter than 26, weight of skull less than 0.7 grams, basilar length less than 29; fromM. e. muricus, in both sexes, by upper parts darker, tone 4 of Chocolate or darker (see description of color), least width of light-colored underparts averaging one-third instead of approximately two-thirds of greatest width of dark-colored upper parts, in males, on the average, tail more than 65, weight of skull more than 0.90 grams, basilar length more than 30.8 mm.; fromM. e. streatori, in both sexes, by upper lips white (not brown), light color of underparts extending down hind legs below knee, depth of skull at posterior border of upper molars less than 7.7 in females and ordinarily less than 9.6 in males.Description.—Size.—Male: One adult and four subadults from Mount Rainier yield average and extreme measurements as follows: Total length, 253 (238-266); length of tail, 75 (70-83); length of hind foot, 31.5 (30-33). Corresponding measurements of 9 subadults from Trout Lake are: 257 (233-282); length of tail, 76 (56-83); length of hind foot, 30.2 (26-33).Female: Of adults, 2 from Mount Rainier and 2 from Trout Lake measure as follows: Total length, 202, 203, 216, 210; length of tail, 54, 52, 57, 51; length of hind foot, 24, 24, 25, 24. The averages for these females are 208, 54, 24.3.Color.—As described inMustela erminea richardsoniiexcept that color sometimes brown in winter (with more smoky tinge than summer coat); upper parts ranging from tone 2 through tones 3 and 4 of Dark Chocolate (pl. 342) into tone 4 of Chocolate (pl. 343) of Oberthür and Dauthenay; underparts (always white in winter) in summer Sulphur Yellow or more whitish; least width of color of underparts averaging, in 5 males from Mount Rainier, 31 (18-45) per cent of greatest width of color of upper parts. Black tip of tail, in same series, averaging 34 (29-40) mm., which is 45 (41-50) per cent of length of tail-vertebrae.Skull.—Male (based on 2 ad. and 13 sad.): See measurements and plates5-7. As described inMustela erminea richardsoniiexcept that: Weight, 1.0 (0.95-1.16) grams; basilar length, 32.3 (30.9-33.4); length of tooth-rows more or less than (about equal to) length of tympanic bulla.Female (illustrated by 5 adults): See measurements and plates12-14. As described inMustela erminea richardsoniiexcept that: Weight, 0.59 (0.53-0.65) grams; basilar length, 28.1 (27.8-28.4); breadth of rostrum ordinarily more than 30 per cent of basilar length.
Type.—Male, subadult, skull and skin; no. 81998, U. S. Nat. Mus., Biol. Surv. Coll.; Trout Lake, Klickitat County, Washington; February 3, 1897; obtained by P. Schmid, original no. 147.
The skin is in brown winter pelage, and appears to have been made up from a skin split along the midventral line from the anus to the forelegs. It probably was dried by a trapper, is well made, and lacks a patch of hair on the left flank but otherwise is in good condition. The skull lacks the central part of the left zygomatic arch and the posterior two-thirds of the right one. The right m2 is represented only by an abortive stump or the broken root, and i1 and i2 on each side are absent; otherwise, the teeth all are present and entire.
Range.—Cascades of Washington from northeastern King County south to Mount Adams. See figures25,27on pages 95, 149.
Characters for ready recognition.—Differs fromM. e. invictaandfallenda, in both sexes, by anterior margin of tympanic bulla flush with squamosal rather than projecting below floor of braincase (difference slight in females), in males hind foot less than 33.5, weight of skull less than 1-1/4 grams, basilar length less than 33.9, in females by total length less than 222, hind foot shorter than 26, weight of skull less than 0.7 grams, basilar length less than 29; fromM. e. muricus, in both sexes, by upper parts darker, tone 4 of Chocolate or darker (see description of color), least width of light-colored underparts averaging one-third instead of approximately two-thirds of greatest width of dark-colored upper parts, in males, on the average, tail more than 65, weight of skull more than 0.90 grams, basilar length more than 30.8 mm.; fromM. e. streatori, in both sexes, by upper lips white (not brown), light color of underparts extending down hind legs below knee, depth of skull at posterior border of upper molars less than 7.7 in females and ordinarily less than 9.6 in males.
Description.—Size.—Male: One adult and four subadults from Mount Rainier yield average and extreme measurements as follows: Total length, 253 (238-266); length of tail, 75 (70-83); length of hind foot, 31.5 (30-33). Corresponding measurements of 9 subadults from Trout Lake are: 257 (233-282); length of tail, 76 (56-83); length of hind foot, 30.2 (26-33).
Female: Of adults, 2 from Mount Rainier and 2 from Trout Lake measure as follows: Total length, 202, 203, 216, 210; length of tail, 54, 52, 57, 51; length of hind foot, 24, 24, 25, 24. The averages for these females are 208, 54, 24.3.
Color.—As described inMustela erminea richardsoniiexcept that color sometimes brown in winter (with more smoky tinge than summer coat); upper parts ranging from tone 2 through tones 3 and 4 of Dark Chocolate (pl. 342) into tone 4 of Chocolate (pl. 343) of Oberthür and Dauthenay; underparts (always white in winter) in summer Sulphur Yellow or more whitish; least width of color of underparts averaging, in 5 males from Mount Rainier, 31 (18-45) per cent of greatest width of color of upper parts. Black tip of tail, in same series, averaging 34 (29-40) mm., which is 45 (41-50) per cent of length of tail-vertebrae.
Skull.—Male (based on 2 ad. and 13 sad.): See measurements and plates5-7. As described inMustela erminea richardsoniiexcept that: Weight, 1.0 (0.95-1.16) grams; basilar length, 32.3 (30.9-33.4); length of tooth-rows more or less than (about equal to) length of tympanic bulla.
Female (illustrated by 5 adults): See measurements and plates12-14. As described inMustela erminea richardsoniiexcept that: Weight, 0.59 (0.53-0.65) grams; basilar length, 28.1 (27.8-28.4); breadth of rostrum ordinarily more than 30 per cent of basilar length.
In comparison withstreatori, skulls of males and females average smaller in every cranial measurement taken. Teeth of about same size and males 9 per cent, and females 8 per cent, lighter. In relation to basilar length, skull of female shallower, tympanic bullae slightly shorter and, on the average, zygomata less expanded.
In comparison withmuricus, males average larger in every measurement taken; 23 per cent heavier; in relation to other dimensions, braincase shallower at anterior end of basioccipital. Females are of about equal size; in relation to other dimensions, braincase shallower and mastoid and zygomatic breadths less.
Comparisons withinvictaandfallendahave been made in the accounts of those subspecies.
Remarks.—This is not a strongly marked race and in most of the characters used for differentiating it from other races it resembles eitherstreatorito the west ormuricusto the southeast. Nevertheless, there is a geographic area, the southern Cascades of Washington, throughout which individual characters are combined in essentially the same way and there are a few features, for instance, smaller skull of the female, in whichgulosadiffers from either of its close relatives. In view of these circumstances and because the animals can not well be included in the subspeciesstreatoriormuricus,gulosais recognized as distinct. The racesgulosaandolympicaare what might be termed weakly differentiated subspecies in contrast to the strongly differentiated subspeciesstreatoriandmuricus.
Of the 21 specimens in winter pelage, 17 are white and four are brown. The brown winter coat is distinctly paler, with more of a smoky tinge, than the brown summer pelage. The light-colored underparts are narrower than in the subspecies immediately to the east but are wider than in the coastal forms to the west. The dark color of the upper parts extends onto the chest in front of the forelegs, as in the coastal forms, in only one of the 13 specimens in summer pelage and in it on one side only. The black tip of the tail is short as in the coastal forms. One specimen is in transitional pelage. It has acquired approximately half of the white winter pelage and was taken on October 12, 1897, at Keechelus Lake.
Specimens examined.—Total number, 38, arranged by counties from north to south. Unless otherwise indicated, specimens are in the U. S. National Museum.Washington.King County: 2 mi. E Skykomish, 2[51].Kittitas County: Keechelus Lake, 3 (1[1]); Martin, 1[1]; Easton, 3.Pierce County: James Lake, 4370 ft., Mt. Rainier, 1; Glacier Basin, 5935 ft., Mt. Rainier, 1; Meslers Ranch, 2000 ft., 1 mi. W Rainier Park, 1.Lewis County: Mt. Rainier Nat'l Park, 5 (1 each from: Paradise Park, 5400 ft.; Reflection Lakes, 4900 ft.; Ohanapecosh [Hot] Springs, 2000 ft.; Tahoma Creek, 1[72]; Bear Prairie); also in Mt. Rainier Nat'l Park, Longmire, 3 (1[72], 1[94]).Skamania County: Mt. St. Helens, 6000 ft., 1.Klickitat County: Trout Lake, 18.
Specimens examined.—Total number, 38, arranged by counties from north to south. Unless otherwise indicated, specimens are in the U. S. National Museum.
Washington.King County: 2 mi. E Skykomish, 2[51].Kittitas County: Keechelus Lake, 3 (1[1]); Martin, 1[1]; Easton, 3.Pierce County: James Lake, 4370 ft., Mt. Rainier, 1; Glacier Basin, 5935 ft., Mt. Rainier, 1; Meslers Ranch, 2000 ft., 1 mi. W Rainier Park, 1.Lewis County: Mt. Rainier Nat'l Park, 5 (1 each from: Paradise Park, 5400 ft.; Reflection Lakes, 4900 ft.; Ohanapecosh [Hot] Springs, 2000 ft.; Tahoma Creek, 1[72]; Bear Prairie); also in Mt. Rainier Nat'l Park, Longmire, 3 (1[72], 1[94]).Skamania County: Mt. St. Helens, 6000 ft., 1.Klickitat County: Trout Lake, 18.
Ermine
Plates7,8,12,13,14and41
Putorius (Arctogale) muricusBangs, Proc. New England Zoöl. Club, 1:71, July 31, 1899.Putorius streatori leptusMerriam, Proc. Biol. Soc. Washington, 16:76, May 29, 1903. Type from Silverton, San Juan County, Colorado.Putorius muricus, Stephens, California Mammals, p. 248, 1906.Putorius cicognani, Taylor, Univ. California Publ. Zoöl., 7:298, June 24, 1911.Mustela streatori leptus, Miller, U. S. Nat. Mus. Bull., 79:96, December 31, 1912; Bailey, N. Amer. Fauna, 35:48, September 5, 1913; Dixon, Journ. Mamm., 12:72, February 12, 1931; Whitlow and Hall, Univ. California Publ. Zoöl., 40:246, September 30, 1933.Mustela muricus, Miller, U. S. Nat. Mus. Bull., 79:96, December 31, 1912; Kellogg, Univ. California Publ. Zoöl., 12:358, January 27, 1916.Mustela cicognanii lepta, Dice, Journ. Mamm., 1:12, November 28, 1919; Hall, Mamm. Nevada, p. 184, July 1, 1946.Mustela rixosa, Seton, Journ. Mamm., 14:70, February 14, 1933.Mustela cicognanii leptus, Miller, Journ. Mamm., 14:368, November 13, 1933; Bailey, N. Amer. Fauna, 55:293, August 29, 1936.Mustela erminea murica, Hall, Journ. Mamm., 26:84, February 27, 1945; Hall, Journ. Mamm., 26:181, July 19, 1945.
Putorius (Arctogale) muricusBangs, Proc. New England Zoöl. Club, 1:71, July 31, 1899.
Putorius streatori leptusMerriam, Proc. Biol. Soc. Washington, 16:76, May 29, 1903. Type from Silverton, San Juan County, Colorado.
Putorius muricus, Stephens, California Mammals, p. 248, 1906.
Putorius cicognani, Taylor, Univ. California Publ. Zoöl., 7:298, June 24, 1911.
Mustela streatori leptus, Miller, U. S. Nat. Mus. Bull., 79:96, December 31, 1912; Bailey, N. Amer. Fauna, 35:48, September 5, 1913; Dixon, Journ. Mamm., 12:72, February 12, 1931; Whitlow and Hall, Univ. California Publ. Zoöl., 40:246, September 30, 1933.
Mustela muricus, Miller, U. S. Nat. Mus. Bull., 79:96, December 31, 1912; Kellogg, Univ. California Publ. Zoöl., 12:358, January 27, 1916.
Mustela cicognanii lepta, Dice, Journ. Mamm., 1:12, November 28, 1919; Hall, Mamm. Nevada, p. 184, July 1, 1946.
Mustela rixosa, Seton, Journ. Mamm., 14:70, February 14, 1933.
Mustela cicognanii leptus, Miller, Journ. Mamm., 14:368, November 13, 1933; Bailey, N. Amer. Fauna, 55:293, August 29, 1936.
Mustela erminea murica, Hall, Journ. Mamm., 26:84, February 27, 1945; Hall, Journ. Mamm., 26:181, July 19, 1945.
Type.—Male, young, skull and skin; no. 9146, collection of E. A. and O. Bangs in Mus. Comp. Zoöl.; Echo, 7500 ft., El Dorado County, California; July 15, 1897; obtained by W. W. Price and E. M. Nutting.The skull has a fracture along the sagittal suture and fractures on the left side of the braincase but these have been glued, and no part of the skull is missing except in the region of the right P4 which part has been shot away. On the left side m2 never developed. Excepting this tooth and the right P4, all the teeth are present and entire. The skin is well made but has the soles of the hind feet turned up.Range.—Near 5300 feet (Denver) to 11000 feet (Santa Fe Baldy); typically boreal but taken in Upper Sonoran Life-zone in winter at Denver; from central and southwestern Montana, southern Idaho, and Blue Mountains of southeastern Washington southward east of the Cascade Divide through the Salmon River Mountains and Sierra Nevada at least into Fresno County of California, in the Great Basin to central Nevada, in the Rocky Mountains into northern New Mexico; eastward to the Black Hills. See figure25on page95.Characters for ready recognition.—Differs fromM. e. invictaby hind foot less than 36 and basilar length less than 35 in males and by hind foot less than 29.5 and basilar length less than 30.5 in females; fromM. e. gulosa, in both sexes, by upper parts lighter, tone 2 of Chocolate or lighter (see description of color), least width of light-colored underparts averaging about two-thirds instead of one-third of greatest width of dark-colored upper parts, in males, on the average, tail less than 65, weight of skull less than 0.90 grams, basilar length less than 30.8 grams; fromM. e. streatori, in both sexes, by upper lips white (not brown), light color of underparts extending down hind leg below knee, depth of skull at posterior border of upper molars less than 7.7 in females and ordinarily less than 9.6 in males, tail less than 62 in males and less than 49 in females.Description.—Size.—Male: An adult from Black Butte, California, measures: Total length, 227; length of tail, 55; length of hind foot, 27. Corresponding measurements of another from Wheeler Peak, Nevada, are: 220, 56, 26. Two subadults from Colorado, one from Crested Butte and another from Coventry, measure, respectively, as follows: 238, 227; 66, 60; 30, 30. An adult from Wheeler Peak, Nevada, weighs 57.7 grams and another from 2 mi. W Black Butte, Calif., 54.5 grams.Female: Two adults from Teton County, Wyoming, measure: Total length, 205, 200; length of tail 52,—; length of hind foot, 23, 23.7. A subadult from 9-1/2 mi. E Pocatello, Idaho, measures: 197, 50, 25. An adult from Wheeler Peak, Nevada, has corresponding measurements of 190, 42, 23, and weighs 33.8 grams.Color.—As described inMustela erminea richardsoniiexcept that upper parts tone 2 or lighter of Chocolate of plate 343 of Oberthür and Dauthenay; underparts white, Pale Buff or with faint wash of Sulphur Yellow; least width of color of underparts in male from Black Butte and one from Wheeler Peak, amounting to 65 and 59 per cent of greatest width of color of upper parts. Black tip of tail, respectively, 28 and 33 mm., which amounts to 51 and 59 per cent of length of tail-vertebrae. In two adult females, one from Teton County, Wyoming, and one from Wheeler Peak, Nevada, the least width of the underparts amounts to 55 and 60 per cent of the greatest width of color of upper parts. Black tip of tail, respectively, 23 and 19 mm., which amounts to 44 and 45 per cent of length of tail-vertebrae.From the other subspecies of small-sized weasels of more northwestern occurrence, namelyanguinae,fallenda,olympica,streatoriandgulosa,muricusdiffers in lighter color of upper parts, wider light-colored underparts and relatively longer black tip of tail.Skull.—Male (illustrated by 5 adults in table of measurements, which see): See plate7. As described inMustela erminea richardsoniiexcept that: Weight, 0.78 (Wheeler Peak) and 0.85 (Black Butte) grams; basilar length, 30.6 (29.8-31.2); length of tooth-rows more or less than (approximately equal to) length of tympanic bulla.Female (illustrated by 6 adults in table of measurements, which see): See plates12-14. As described inMustela erminea richardsoniiexcept that: Weight, 0.60 (0.575-0.645); basilar length, 28.0 (27.3-29.4); breadth of rostrum approximately 30 per cent of basilar length.
Type.—Male, young, skull and skin; no. 9146, collection of E. A. and O. Bangs in Mus. Comp. Zoöl.; Echo, 7500 ft., El Dorado County, California; July 15, 1897; obtained by W. W. Price and E. M. Nutting.
The skull has a fracture along the sagittal suture and fractures on the left side of the braincase but these have been glued, and no part of the skull is missing except in the region of the right P4 which part has been shot away. On the left side m2 never developed. Excepting this tooth and the right P4, all the teeth are present and entire. The skin is well made but has the soles of the hind feet turned up.
Range.—Near 5300 feet (Denver) to 11000 feet (Santa Fe Baldy); typically boreal but taken in Upper Sonoran Life-zone in winter at Denver; from central and southwestern Montana, southern Idaho, and Blue Mountains of southeastern Washington southward east of the Cascade Divide through the Salmon River Mountains and Sierra Nevada at least into Fresno County of California, in the Great Basin to central Nevada, in the Rocky Mountains into northern New Mexico; eastward to the Black Hills. See figure25on page95.
Characters for ready recognition.—Differs fromM. e. invictaby hind foot less than 36 and basilar length less than 35 in males and by hind foot less than 29.5 and basilar length less than 30.5 in females; fromM. e. gulosa, in both sexes, by upper parts lighter, tone 2 of Chocolate or lighter (see description of color), least width of light-colored underparts averaging about two-thirds instead of one-third of greatest width of dark-colored upper parts, in males, on the average, tail less than 65, weight of skull less than 0.90 grams, basilar length less than 30.8 grams; fromM. e. streatori, in both sexes, by upper lips white (not brown), light color of underparts extending down hind leg below knee, depth of skull at posterior border of upper molars less than 7.7 in females and ordinarily less than 9.6 in males, tail less than 62 in males and less than 49 in females.
Description.—Size.—Male: An adult from Black Butte, California, measures: Total length, 227; length of tail, 55; length of hind foot, 27. Corresponding measurements of another from Wheeler Peak, Nevada, are: 220, 56, 26. Two subadults from Colorado, one from Crested Butte and another from Coventry, measure, respectively, as follows: 238, 227; 66, 60; 30, 30. An adult from Wheeler Peak, Nevada, weighs 57.7 grams and another from 2 mi. W Black Butte, Calif., 54.5 grams.
Female: Two adults from Teton County, Wyoming, measure: Total length, 205, 200; length of tail 52,—; length of hind foot, 23, 23.7. A subadult from 9-1/2 mi. E Pocatello, Idaho, measures: 197, 50, 25. An adult from Wheeler Peak, Nevada, has corresponding measurements of 190, 42, 23, and weighs 33.8 grams.
Color.—As described inMustela erminea richardsoniiexcept that upper parts tone 2 or lighter of Chocolate of plate 343 of Oberthür and Dauthenay; underparts white, Pale Buff or with faint wash of Sulphur Yellow; least width of color of underparts in male from Black Butte and one from Wheeler Peak, amounting to 65 and 59 per cent of greatest width of color of upper parts. Black tip of tail, respectively, 28 and 33 mm., which amounts to 51 and 59 per cent of length of tail-vertebrae. In two adult females, one from Teton County, Wyoming, and one from Wheeler Peak, Nevada, the least width of the underparts amounts to 55 and 60 per cent of the greatest width of color of upper parts. Black tip of tail, respectively, 23 and 19 mm., which amounts to 44 and 45 per cent of length of tail-vertebrae.
From the other subspecies of small-sized weasels of more northwestern occurrence, namelyanguinae,fallenda,olympica,streatoriandgulosa,muricusdiffers in lighter color of upper parts, wider light-colored underparts and relatively longer black tip of tail.
Skull.—Male (illustrated by 5 adults in table of measurements, which see): See plate7. As described inMustela erminea richardsoniiexcept that: Weight, 0.78 (Wheeler Peak) and 0.85 (Black Butte) grams; basilar length, 30.6 (29.8-31.2); length of tooth-rows more or less than (approximately equal to) length of tympanic bulla.
Female (illustrated by 6 adults in table of measurements, which see): See plates12-14. As described inMustela erminea richardsoniiexcept that: Weight, 0.60 (0.575-0.645); basilar length, 28.0 (27.3-29.4); breadth of rostrum approximately 30 per cent of basilar length.
In comparison withstreatori, males average smaller in every measurement taken with no overlap in most dimensions; 25 per cent lighter; anterior margin of tympanic bulla more nearly flush with squamosal, that is to say less protruded from braincase; in relation to other dimensions of skull, braincase shallower anteriorly (at plane of last molars) and deeper posteriorly (at anterior end of basioccipital). Females average smaller in every measurement taken except mastoid and zygomatic breadths which are actually more; 6 per cent lighter; in relation to other parts of skull, preorbital and interorbital parts slightly smaller; in relation to length of skull, braincase shallower. Comparison withinvictaandgulosais made in the accounts of those subspecies.
Remarks.—The smallest males of the entire species are of this subspecies and the females of it are barely larger than those ofolympicaandgulosaand hence are among the three smallest. The material now available consists only of one or a few specimens from each of several widely separated localities. If as many specimens per unit area were available as there are of the speciesM. ermineafrom southern British Columbia, geographic variation warranting the division ofmuricusinto more than one subspecies might be revealed. Evidence pointing in this direction is comprised in the pale color and small size of the pair of adults from Wheeler Peak on the eastern border of Nevada; the suggestion is that there is a distinct pale race of small individuals in the isolated spots of boreal life-zone in the mountains of the desert. The color and size of the specimens from the Toyabe Mountains, and that from the Pine Forest Mountains, both places also in Nevada, nevertheless, lend no support to this suggestion. Comparison of specimens from the Rocky Mountains of Colorado with those from the Sierra Nevada of California gives no basis for recognizing more than one subspecies. Therefore,Putorius streatori leptusMerriam with type locality at Silverton, San Juan County, Colorado, falls as a synonym of the earlier namedPutorius (Arctogale) muricusBangs with type locality at Echo, El Dorado County, California. Furthermore, specimens from northern New Mexico, the southernmost known area of occurrence for the subspecies (and for the species), are as large as specimens from far north in the range of the subspecies, say, in northwestern Wyoming; there is therefore no evidence of progressive decrease in size to the southward as in advance of study I supposed existed inmuricus. This erroneous supposition was held because I knew that there was a decrease in size to the southward in the species as a whole and also in each of the subspeciesrichardsoniiandinvictadirectly to the north ofmuricus.
Intergradation withinvictais shown by specimens from southwestern Montana. Where the margins of the geographic ranges ofinvictaandmuricusapproach one another elsewhere, low-lying territory, zonally unsuited to the existence of the species, occurs along the Snake and Columbia rivers, and precludes any chance of intergradation except around the head of the Snake River Plains. Two specimens, here referred tomuricus, from Siskiyou County, California, in both color and cranial characters, are intergrades withstreatoriand might be referred with almost equal propriety tostreatori.
Specimens examined.—Total number, 52, arranged alphabetically by states, then by counties from north to south within each state. Unless otherwise indicated, specimens are in the Museum of Vertebrate Zoölogy, University of California at Berkeley.California.Siskiyou County: head of Rush Creek, 6400 ft., 1; Castle Lake, 5434 ft., 1.Tehama County: 2 mi. W Black Butte, 6800 ft., 1.Placer County: ridge W of Tahoe Pines, Lake Tahoe, 1; Blackwood Creek, 6250 ft., near Tahoe Pines, 1.El Dorado County: Fallen Leaf Lake, 6500 ft., 1[33]; Echo, 1[75].Tuolumne County: Ten Lakes, 9200 ft., Yosemite Park, 1.Mariposa County: Vogelsang Lake, 10350 ft., Yosemite Park, 1.Mono County: Mammoth, 1[59].Colorado.Rio Blanco County: Marvine, 1.Boulder County: Camp Albion, 10600 ft., 1[60]; Boulder, 1[91].Denver County: Denver, 1[57].Park County: Jefferson, 1[57].Gunnison County: near Placita in Gunnison County, 1[26]; Crested Butte, 9000 ft., 3 (1[91], 2[19]).El Paso County: Turkey Creek, SW Colorado Springs, 6000 ft., 1[19].Chaffee County: Arbourville, 1[91]; Hancock, 1.Montrose County: Coventry, 6800 ft., 1[19].San Juan County: Silverton, 1[91]; in San Juan County above timberline, 1[87].Idaho.Bannock County: West Fork of Rapid Creek, 9-1/2 mi. E Pocatello, 1.Montana.Meagher County: Camas Creek, Big Belt Mts., 4 mi. S Ft. Logan, 1[91].Beaverhead County: Donovan, 1[91].Countyin question: Yellowstone Park, 1[75].Nevada.Humboldt County: Alder Creek, 6000 ft., Pine Forest Mts., 1.Ormsby County: 1/2 mi. S Marlette Lake, 8150 ft., 1.Nye County: South Twin River, Toyabe Mts., 1[91].White Pine County: Baker Creek (8500 ft., 8675 ft., 11100 ft.), 3.New Mexico.Taos County: Twining, 10700 ft., 1[91].Sandoval County: 9 mi. E Cuba, 9000 ft., 1.Santa Fe County: Saddle S of Santa Fe Baldy, 11000 ft., Santa Fe Range, 1[1].Oregon.Wasco County: Mill Creek, 20 mi. W Warmsprings, 1[91].Klamath County: Fort Klamath, 1[91].South Dakota.Pennington County: 4 mi. SE Hill City, 5300 ft., 2[76]; Pfander's Ranch, 3 mi. SSE Hill City, 5300 ft., 1[76]; Palmer Gulch, 3 mi. SE Hill City, 5300 ft., 1[76]; Spring Creek, 2 mi. W Oreville, 5500 ft., 1[76].Custer County: 1/2 mi. E Sylvan Lake, 6250 ft., 1[76].Washington.Columbia County: Butte Creek, 1; Stayawhile Spring, 5150 ft., 1.Wyoming.Crook County: 5 mi. NW Sundance, 5900 ft., 1[93].Teton County: Whetstone Creek, 2[76]; 1/4 mi. E Moran, 6700 ft., 1[93].Sublette County: 1/2 mi. NE Pinedale, 7500 ft., 1[93].Albany County: 30 mi. N and 10 mi. E Laramie, 6560 ft., 1[93]; 26 mi. N and 4-1/2 mi. E Laramie, 6960 ft., 1[93].Carbon County: 8 mi. N and 19-1/2 mi. E Savery, 8800 ft., 2[93].
Specimens examined.—Total number, 52, arranged alphabetically by states, then by counties from north to south within each state. Unless otherwise indicated, specimens are in the Museum of Vertebrate Zoölogy, University of California at Berkeley.
California.Siskiyou County: head of Rush Creek, 6400 ft., 1; Castle Lake, 5434 ft., 1.Tehama County: 2 mi. W Black Butte, 6800 ft., 1.Placer County: ridge W of Tahoe Pines, Lake Tahoe, 1; Blackwood Creek, 6250 ft., near Tahoe Pines, 1.El Dorado County: Fallen Leaf Lake, 6500 ft., 1[33]; Echo, 1[75].Tuolumne County: Ten Lakes, 9200 ft., Yosemite Park, 1.Mariposa County: Vogelsang Lake, 10350 ft., Yosemite Park, 1.Mono County: Mammoth, 1[59].
Colorado.Rio Blanco County: Marvine, 1.Boulder County: Camp Albion, 10600 ft., 1[60]; Boulder, 1[91].Denver County: Denver, 1[57].Park County: Jefferson, 1[57].Gunnison County: near Placita in Gunnison County, 1[26]; Crested Butte, 9000 ft., 3 (1[91], 2[19]).El Paso County: Turkey Creek, SW Colorado Springs, 6000 ft., 1[19].Chaffee County: Arbourville, 1[91]; Hancock, 1.Montrose County: Coventry, 6800 ft., 1[19].San Juan County: Silverton, 1[91]; in San Juan County above timberline, 1[87].
Idaho.Bannock County: West Fork of Rapid Creek, 9-1/2 mi. E Pocatello, 1.
Montana.Meagher County: Camas Creek, Big Belt Mts., 4 mi. S Ft. Logan, 1[91].Beaverhead County: Donovan, 1[91].Countyin question: Yellowstone Park, 1[75].
Nevada.Humboldt County: Alder Creek, 6000 ft., Pine Forest Mts., 1.Ormsby County: 1/2 mi. S Marlette Lake, 8150 ft., 1.Nye County: South Twin River, Toyabe Mts., 1[91].White Pine County: Baker Creek (8500 ft., 8675 ft., 11100 ft.), 3.
New Mexico.Taos County: Twining, 10700 ft., 1[91].Sandoval County: 9 mi. E Cuba, 9000 ft., 1.Santa Fe County: Saddle S of Santa Fe Baldy, 11000 ft., Santa Fe Range, 1[1].
Oregon.Wasco County: Mill Creek, 20 mi. W Warmsprings, 1[91].Klamath County: Fort Klamath, 1[91].
South Dakota.Pennington County: 4 mi. SE Hill City, 5300 ft., 2[76]; Pfander's Ranch, 3 mi. SSE Hill City, 5300 ft., 1[76]; Palmer Gulch, 3 mi. SE Hill City, 5300 ft., 1[76]; Spring Creek, 2 mi. W Oreville, 5500 ft., 1[76].Custer County: 1/2 mi. E Sylvan Lake, 6250 ft., 1[76].
Washington.Columbia County: Butte Creek, 1; Stayawhile Spring, 5150 ft., 1.
Wyoming.Crook County: 5 mi. NW Sundance, 5900 ft., 1[93].Teton County: Whetstone Creek, 2[76]; 1/4 mi. E Moran, 6700 ft., 1[93].Sublette County: 1/2 mi. NE Pinedale, 7500 ft., 1[93].Albany County: 30 mi. N and 10 mi. E Laramie, 6560 ft., 1[93]; 26 mi. N and 4-1/2 mi. E Laramie, 6960 ft., 1[93].Carbon County: 8 mi. N and 19-1/2 mi. E Savery, 8800 ft., 2[93].
Plates7,12,13and14
Putorius cicognanii angustidensBrown, Mem. Amer. Mus. Nat. Hist., 9 (pt 4):181, pl. 17, 1908.Mustela cicognanii angustidens, Hay, Iowa Geol. Surv. Bull., 23:32, 1914; Hay, Carnegie Inst. Washington, Pub. no. 322A:252, October 15, 1924; Hay,ibid., Pub. no. 390 (vol. 2): 528, 1930; Hall,ibid., Pub. no. 473:111, 112, November 20, 1936.Type.—Female, adult, skull and lower jaws lacking zygomata, right P2 and incisors, no. 12432, Amer. Mus. Nat. Hist.; from Conard Fissure, four miles west of Willcockson, Newton County, Arkansas; obtained sometime in the period 1903 to 1905 inclusive (see plates8,14).Range.—Known only from the Pleistocene deposit in Conard Fissure, at the type locality in northern Arkansas.Description.—Skull.—Male (based on nos. 12437, 12441 and 12444): See measurements and plates7and8; weight, unknown; basilar length, 38.1 (36.6-39.2); length of tooth-rows more than length of tympanic bulla; breadth of rostrum measured across lacrimal processes less than a third of basilar length; interorbital breadth ordinarily equal to distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth probably averaging approximately the same as distance between last upper molar and jugular foramen.Female (based on nos. 11766 and 12435): See measurements and plates 8, 12-14; weight, unknown; basilar length, 34.0 (32.5-35.1); length of tooth-rows more than length of tympanic bulla; breadth of rostrum about equal to (more or less than) 30 per cent of basilar length; interorbital breadth less than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth probably less than distance between last upper molar and jugular foramen.Comparison of the cranial description given above with those of the American races ofermineafrom the far north will show that many characters are held in common—more than with more southern subspecies oferminea.
Putorius cicognanii angustidensBrown, Mem. Amer. Mus. Nat. Hist., 9 (pt 4):181, pl. 17, 1908.
Mustela cicognanii angustidens, Hay, Iowa Geol. Surv. Bull., 23:32, 1914; Hay, Carnegie Inst. Washington, Pub. no. 322A:252, October 15, 1924; Hay,ibid., Pub. no. 390 (vol. 2): 528, 1930; Hall,ibid., Pub. no. 473:111, 112, November 20, 1936.
Type.—Female, adult, skull and lower jaws lacking zygomata, right P2 and incisors, no. 12432, Amer. Mus. Nat. Hist.; from Conard Fissure, four miles west of Willcockson, Newton County, Arkansas; obtained sometime in the period 1903 to 1905 inclusive (see plates8,14).
Range.—Known only from the Pleistocene deposit in Conard Fissure, at the type locality in northern Arkansas.
Description.—Skull.—Male (based on nos. 12437, 12441 and 12444): See measurements and plates7and8; weight, unknown; basilar length, 38.1 (36.6-39.2); length of tooth-rows more than length of tympanic bulla; breadth of rostrum measured across lacrimal processes less than a third of basilar length; interorbital breadth ordinarily equal to distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth probably averaging approximately the same as distance between last upper molar and jugular foramen.
Female (based on nos. 11766 and 12435): See measurements and plates 8, 12-14; weight, unknown; basilar length, 34.0 (32.5-35.1); length of tooth-rows more than length of tympanic bulla; breadth of rostrum about equal to (more or less than) 30 per cent of basilar length; interorbital breadth less than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth probably less than distance between last upper molar and jugular foramen.
Comparison of the cranial description given above with those of the American races ofermineafrom the far north will show that many characters are held in common—more than with more southern subspecies oferminea.
Remarks.—The ten specimens studied by the writer fall into two groups of six larger individuals and four smaller. Upon comparing these with each sex of the three species of American Recent weasels,frenata,ermineaandrixosa, it is seen that size, and to some degree shape, rule out of consideration both sexes ofrixosaand also males offrenata. Thus we are left with females offrenataand males and females oferminea. So far as size is concerned, it can be assumed that the larger specimens are females offrenataand that the smaller are males oferminea. This assumption has in its favor also, the fact that the postglenoidal length of the skull accords with that in Recent specimens. The difference in this regard in Recent animals is that the postglenoidal length of the skull, expressed as a percentage of the total (condylobasal) length of the skull, amounts to:
infrenatainerminea♂ ordinarily less than 46♂ ordinarily more than 46♀ less than 47♀ more than 48
In the fossils the percentage for the larger skulls is 46; for the smaller skulls it is 48.
It may be that the ten fossil skulls are six femalefrenataand four maleermineabut I think not. In the first place a skull of different shape, seemingly of thefrenatastock, is known from the deposit and it is almost certain that two subspecies of the same species would not occur at the same place at the same time. It is possible, of course, that parts of the deposits were laid down at times so far apart that a shift in geographic range of two subspecies had occurred. This one skull, seemingly of thefrenatastock, is the type ofPutorius gracilisBrown (see p. 404) and was regarded as the only known specimen ofgracilis. Regardless of the specific identity of this one specimen namedgracilis, the chances of obtaining otherwise from a deposit, like that in Conard Fissure, six females offrenataand four males ofermineawithout a malefrenataor a female ofermineacoming to light are so slight as strongly to incline me to the view that the six larger specimens are males of the same species to which the 4 smaller specimens belong. By either this interpretation, or the one initially considered (of femalefrenataand maleerminea), the animals from the fissure are at least subspecifically distinct from any American Recent weasel. Furthermore, by this latter interpretation each sex of this weasel,angustidens, is intermediate between thefrenataandermineastocks in the feature of postglenoidal length which feature, at any place where the two Recent species occur together, serves to distinguish one from the other. In the northernmost subspecies oferminea(arcticafor example) the postglenoidal length in some males is no longer than in males offrenata. Considering general size,angustidensagrees better withermineathan withfrenataand this circumstance has influenced me to placeangustidensas a subspecies oferminea.
Today,ermineais not known to occur nearer Conard Fissure than northern Iowa, more than 400 miles to the northward. In comparison with the race there,bangsi, males ofangustidensare of approximately the same size but in the shorter distance between the glenoid fossa and anterior margin of the tympanic bulla, and also in the lesser postglenoidal length of the skull,angustidensresembles the northernmost American subspecies oferminea. Females ofangustidensdiffer more from any living weasel than the males do. The females are much larger than those ofbangsi, and among living American races ofermineamost closely resemble intergrades betweenarcticaandrichardsoniiwhich intergrades are found approximately 1700 miles to the north of Conard Fissure. In females, the preorbital part of the skull inM. e. arcticais broader and inM. e. richardsoniinarrower than inangustidens. If it seems strange that females ofangustidensresemble one subspecies whereas males, in size, resemble another subspecies almost a thousand miles distant, it should be remembered that the degree of sexual dimorphism varies much from one subspecies to another in the Recent animals. An example is furnished byMustela erminea fallendaandMustela erminea invicta.
The assemblage of mammals from Conard Fissure includes several species of boreal predilections which, likeMustela erminea, now occur only much farther north than Arkansas. At one time the edge of the sheet of ice was only about 200 miles north of Arkansas. It may be significant that the cranial characters of the female ermine from the Fissure, and qualitative cranial characters of males from there, are most nearly approximated among Recent weasels by those which live along the southern edge of the frozen tundra.
In view of what has been said, the possibility should be considered that the distinctive cranial features ofangustidensmay be the result of evolutionary change in time as well as of geographic variation resulting from horizontal placement.