Cottontail (genusSylvilagus).—Hamilton (1933:33), as noted above, found remains of cottontail in the digestive tracts of ermine that had been trapped for fur in winter. Possibly these remains were bait that had been placed at traps.
Snowshoe rabbit (Lepus americanus).—Morse (1939:210) in a study of predation on hares and grouse in the period of notable decimation of these two game species in 1935-1936 in the Cloquet Valley State Forest, in St. Louis County, Minnesota, found that "weasel predation on hares appeared to be of very low incidence or altogether lacking."
Wild birds (Class Aves).—Aldous and Manweiler (1942), as noted above, found that the remains of birds constituted five per cent by volume of the food of the ermine in winter in Minnesota.
Chicken (genusGallus).—Criddle and Criddle (1925:145), who published relatively extensive data on the three species of weasels of Manitoba, write that: "We have no record of Bonaparte's weasel killing poultry, and we doubt whether it ever does so." However, Soper (1919:46) investigated the excited cackling of a hen brooding chicks at night and found a solitary ermine that had killed three chicks and that had the remainder under very active scrutiny.
Leopard frog (Rana pipiens).—One frog was found in a male ermine on November 20, 1931, in New York by Hamilton (1933:300).
Fish (Class Pisces).—Aldous and Manweiler (1942) found fragments of a small fish in one of 60 stomachs of ermine from Minnesota.
Earthworm (Phylum Annelida).—Osgood (1936:64), presumably at Rutland, Vermont, observed a pair of weasels from 2:15 P.M. to 5:00 P.M., in a barn and saw the female in that time make many trips for food for her young. Only earthworms were brought. Fifty traps in an adjacent, swampy field caught only one bull frog and no mice indicating that mice had been eliminated from the foraging territory of the ermine.
In handling food, Dice (1921:22) noted that the Alaskan ermine did not use the feet but only the mouth.
Litters of 4, 4, 7, 7, and 8, yielding an average of 6 young per litter have been recorded from the northeastern United States by Hamilton (1933:327). He (op. cit.:321-325) described animals one day old from New York State as being flesh-colored, having the long neck of the adult and a fine growth of white hair two milli meters in length, on the dorsal surface of the neck, that foreshadows the mane or pompadour that is prominent from the 14th to the 21st day of life. Six animals, when one day old averaged 1.7 grams in weight, which was three per cent of the weight of an adult female and one and one half per cent of the weight of an adult male. At two weeks of age the heavy brown mane stood out in marked contrast to the rest of the scantily, white-furred animal. The eyes opened on the thirty-fifth day of life.
Fig. 24.Mustela erminea richardsonii, adult female, Catalogue Number 14866, U. S. Nat. Mus., Fort Chimo, Ungava. × 1/2.Ventral view of body of a pregnant female to show details of mastology. Note the five pairs of mammae characteristic of weasels, and the uneven arrangement of mammae of the two sides which is also common among weasels.
Fig. 24.Mustela erminea richardsonii, adult female, Catalogue Number 14866, U. S. Nat. Mus., Fort Chimo, Ungava. × 1/2.Ventral view of body of a pregnant female to show details of mastology. Note the five pairs of mammae characteristic of weasels, and the uneven arrangement of mammae of the two sides which is also common among weasels.
Fig. 24.Mustela erminea richardsonii, adult female, Catalogue Number 14866, U. S. Nat. Mus., Fort Chimo, Ungava. × 1/2.
Ventral view of body of a pregnant female to show details of mastology. Note the five pairs of mammae characteristic of weasels, and the uneven arrangement of mammae of the two sides which is also common among weasels.
Fig. 25.Map showing geographic ranges of the subspecies ofMustela ermineain the New World.
Fig. 25.Map showing geographic ranges of the subspecies ofMustela ermineain the New World.
Fig. 25.Map showing geographic ranges of the subspecies ofMustela ermineain the New World.
For rearing their young, ermines live in burrows. Bishop (1923), in Albany, New York, found a burrow occupied by four young and a pair of adults. The burrow had many galleries and contained a nest constructed of rat fur, fine grass and fragments of leaves. At Woods Lake, Fresno County, California, in early August, Ingles observed (1942) some young and at least one adult at their den which was in a burrow beneath a hollow tree. The ermines used the hollow root and the hollow tree as well as the burrow beneath. Seton (1929 (2):591) quotes S. Eldon Percival, of Barretts Rapids, Ontario, as finding the living quarters of an ermine in unthreshed grain stacked in a barn and says (op. cit.:590) that John Burroughs dug out a nest, composed of leaves and the fur of mice and moles, two or three handfuls in bulk, from a cavity the size of a hat, arched over with a fine network of tree roots.
Four instances in which the male as well as the female was present at a den containing young are cited by Hamilton (1933:328) and he gives some evidence, although not at all conclusive, that "adults customarily pair, or at least run together, at times other than the breeding season." No other writers remark on this matter. I doubt that adult ermines are associated in pairs for most of the year but such may be the case.
Ermine
Plates2,3,4,9,10,11and41
Putorius arcticusMerriam, N. Amer. Fauna, 11:15, pl. 2, figs. 1, 1a, and pl. 5, figs. 6, 6a, June 30, 1896.Putorius(Gale)erminea, Coues, Fur-bearing animals, p. 109, 1877 (part).Putorius richardsonii, Bangs, Proc. Biol. Soc. Washington, 10:16, pl. 1, figs. 3, 3a, pl. 2, figs. 3, 3a, and pl. 3, figs. 6, 6a, February 25, 1896 (part).Putorius cicognanii alascensis, Osgood, N. Amer. Fauna, 19:43, October 6, 1900.Putorius kadiacensis, Osgood, N. Amer. Fauna, 21:69, September 26, 1901.Putorius audaxBarrett-Hamilton, Ann. and Mag. Nat. Hist., 13(ser. 7):392, May, 1904, type from Discovery Bay, Ellesmere Island.Putorius alascensis, Heller, Univ. California Publ. Zoöl., 5:345, March 5, 1910.Mustela arctica arctica, Miller, U. S. Nat. Mus. Bull., 79:97, December 31, 1912; Dice, Journ. Mamm., 2:22, February 10, 1921.Mustela arctica, Hall, Univ. California Publ. Zoöl., 30:420, March 19, 1929.Mustela erminea arctica, Ognev, The mammals of U.S.S.R. and adjacent countries, 3:31, 1935; Hall, Proc. California Acad. Sci., 23:559, August 22, 1944; Hall, Journ. Mamm., 26:179, July 19, 1945.
Putorius arcticusMerriam, N. Amer. Fauna, 11:15, pl. 2, figs. 1, 1a, and pl. 5, figs. 6, 6a, June 30, 1896.
Putorius(Gale)erminea, Coues, Fur-bearing animals, p. 109, 1877 (part).
Putorius richardsonii, Bangs, Proc. Biol. Soc. Washington, 10:16, pl. 1, figs. 3, 3a, pl. 2, figs. 3, 3a, and pl. 3, figs. 6, 6a, February 25, 1896 (part).
Putorius cicognanii alascensis, Osgood, N. Amer. Fauna, 19:43, October 6, 1900.
Putorius kadiacensis, Osgood, N. Amer. Fauna, 21:69, September 26, 1901.
Putorius audaxBarrett-Hamilton, Ann. and Mag. Nat. Hist., 13(ser. 7):392, May, 1904, type from Discovery Bay, Ellesmere Island.
Putorius alascensis, Heller, Univ. California Publ. Zoöl., 5:345, March 5, 1910.
Mustela arctica arctica, Miller, U. S. Nat. Mus. Bull., 79:97, December 31, 1912; Dice, Journ. Mamm., 2:22, February 10, 1921.
Mustela arctica, Hall, Univ. California Publ. Zoöl., 30:420, March 19, 1929.
Mustela erminea arctica, Ognev, The mammals of U.S.S.R. and adjacent countries, 3:31, 1935; Hall, Proc. California Acad. Sci., 23:559, August 22, 1944; Hall, Journ. Mamm., 26:179, July 19, 1945.
Type.—Male, adult, skull and skin; no. 14062/23010, U. S. Nat. Mus.; Point Barrow, Alaska; July 16, 1883; obtained by John Murdock, original no. 1672.The skull has a fracture, on the dorsal surface, extending from the anterior nares to the interorbital constriction and another fracture on the left margin of the nasal bone. The middle of the left zygomatic arch is broken away. Otherwise the skull is complete. Right incisor one, above and below, are missing. Otherwise the teeth are present and entire. The skin is in the brown summer pelage, well made, in a good state of preservation, and shows no obvious signs of fading.Range.—Arctic regions of Alaska and western Canada from the Pacific Ocean to Smith Sound; from the northern limit of land south approximately to a line from Skagway through Ft. Goodhope, north shore of Great Bear Lake, south shore of Clinton Colden Lake, north shore of Baker Lake, west end of Wagner Bay to south end of Committee Bay. See figure25on page95.Characters for ready recognition.—Differs fromM. e. polarisin darker upper parts (Raw Umber rather than Buckthorn Brown) and less intensely colored underparts that are Sulphur Yellow, Colonial Buff or Primrose Yellow rather than Buff Yellow; fromM. e. semplei, in males, in that hind foot more than 44 and basilar length more than 41 and in that females average larger, the skulls of females being only about 11 per cent heavier; fromM. e. kadiacensisin hind foot more than 33 in females, zygomatic breadth amounting to more, rather than less, than distance between last upper molar and jugular foramen irrespective of sex; fromM. e. richardsonii,alascensis,salvaandinitis, both sexes so far as known, by proximal two-thirds of under side of tail colored same as underparts rather than same as upper parts, and by zygomatic breadth amounting to more, rather than less, than distance between last upper molar and jugular foramen.Description.—Size.—Male: Six adults from Tanana, Alaska, yield average and extreme measurements as follows: Total length, 336 (310-350); length of tail, 93 (84-105); length of hind foot, 49 (45-51).Female: Five adults, one each from Alatna River, mountains near Eagle, Kamarkak in Alaska, Arctic Red River and Baillie Island in Canada, yield average and extreme measurements as follows: Total length, 285 (272-304); length of tail, 77 (68-95); length of hind foot, 39 (34-43).Weight of 5 subadult males from Tanana is 206 (163-248) grams; adults would be heavier.Color.—Winter pelage all white except tip of tail. Summer pelage with upper parts uniform in color and Raw Umber or darker (16n) of Ridgway and about tones 2 to 3 of Chocolate of Oberthür and Dauthenay, pl. 343, but in autumn some specimens have more light red than tones 2 or 3. Underparts Sulphur Yellow, Colonial Buff, or Primrose Yellow, often white on chin and insides of forelegs; color of underparts extends narrowly over upper lips, distally on posterior sides of forelegs onto antipalmar surface of forefeet, onto proximal two-thirds or three-fourths of underside of tail as length of tail is measured along tail-vertebrae, on medial sides of hind legs to a point between knee and ankle but reappears on antiplantar faces of toes and in some individuals is narrowly continuous onto toes; rim of ear in some specimens with short, white or pale hairs giving ears distinct whitish border; least width of color of underparts averaging, in adult males from Alaska, 65 (46-93) per cent of greatest width of color of upper parts. Black tip of tail in 5 males in winter pelage from Tanana averaging 84 (70-93) mm. which is 91 (75-107) per cent of length of tail-vertebrae.Skull.—Male (based on 5 adult topotypes): See measurements and plates2-4. As described inMustela erminea richardsoniiexcept that: Weight, 3.5 (3.1-3.9) grams; basilar length 42.5 (41.8-43.3); length of tooth-rows more than length of tympanic bulla; breadth of rostrum measured across lacrimal processes averaging more than a third of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth more than distance between last upper molar and jugular foramen.Female (based on 2 adult topotypes and 2 adults and 4 subadults from central Alaska): See measurements and plates9-11. As described inMustela erminea richardsoniiexcept that: Weight, 1.5 (1.2-2.0) grams; basilar length, 35.7 (34.5-37.0); length of tooth-rows more than length of tympanic bulla; breadth of rostrum more than 30 per cent of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth more than distance between last upper molar and jugular foramen (except in specimens from Ellesmere Island where two distances are approximately equal).
Type.—Male, adult, skull and skin; no. 14062/23010, U. S. Nat. Mus.; Point Barrow, Alaska; July 16, 1883; obtained by John Murdock, original no. 1672.
The skull has a fracture, on the dorsal surface, extending from the anterior nares to the interorbital constriction and another fracture on the left margin of the nasal bone. The middle of the left zygomatic arch is broken away. Otherwise the skull is complete. Right incisor one, above and below, are missing. Otherwise the teeth are present and entire. The skin is in the brown summer pelage, well made, in a good state of preservation, and shows no obvious signs of fading.
Range.—Arctic regions of Alaska and western Canada from the Pacific Ocean to Smith Sound; from the northern limit of land south approximately to a line from Skagway through Ft. Goodhope, north shore of Great Bear Lake, south shore of Clinton Colden Lake, north shore of Baker Lake, west end of Wagner Bay to south end of Committee Bay. See figure25on page95.
Characters for ready recognition.—Differs fromM. e. polarisin darker upper parts (Raw Umber rather than Buckthorn Brown) and less intensely colored underparts that are Sulphur Yellow, Colonial Buff or Primrose Yellow rather than Buff Yellow; fromM. e. semplei, in males, in that hind foot more than 44 and basilar length more than 41 and in that females average larger, the skulls of females being only about 11 per cent heavier; fromM. e. kadiacensisin hind foot more than 33 in females, zygomatic breadth amounting to more, rather than less, than distance between last upper molar and jugular foramen irrespective of sex; fromM. e. richardsonii,alascensis,salvaandinitis, both sexes so far as known, by proximal two-thirds of under side of tail colored same as underparts rather than same as upper parts, and by zygomatic breadth amounting to more, rather than less, than distance between last upper molar and jugular foramen.
Description.—Size.—Male: Six adults from Tanana, Alaska, yield average and extreme measurements as follows: Total length, 336 (310-350); length of tail, 93 (84-105); length of hind foot, 49 (45-51).
Female: Five adults, one each from Alatna River, mountains near Eagle, Kamarkak in Alaska, Arctic Red River and Baillie Island in Canada, yield average and extreme measurements as follows: Total length, 285 (272-304); length of tail, 77 (68-95); length of hind foot, 39 (34-43).
Weight of 5 subadult males from Tanana is 206 (163-248) grams; adults would be heavier.
Color.—Winter pelage all white except tip of tail. Summer pelage with upper parts uniform in color and Raw Umber or darker (16n) of Ridgway and about tones 2 to 3 of Chocolate of Oberthür and Dauthenay, pl. 343, but in autumn some specimens have more light red than tones 2 or 3. Underparts Sulphur Yellow, Colonial Buff, or Primrose Yellow, often white on chin and insides of forelegs; color of underparts extends narrowly over upper lips, distally on posterior sides of forelegs onto antipalmar surface of forefeet, onto proximal two-thirds or three-fourths of underside of tail as length of tail is measured along tail-vertebrae, on medial sides of hind legs to a point between knee and ankle but reappears on antiplantar faces of toes and in some individuals is narrowly continuous onto toes; rim of ear in some specimens with short, white or pale hairs giving ears distinct whitish border; least width of color of underparts averaging, in adult males from Alaska, 65 (46-93) per cent of greatest width of color of upper parts. Black tip of tail in 5 males in winter pelage from Tanana averaging 84 (70-93) mm. which is 91 (75-107) per cent of length of tail-vertebrae.
Skull.—Male (based on 5 adult topotypes): See measurements and plates2-4. As described inMustela erminea richardsoniiexcept that: Weight, 3.5 (3.1-3.9) grams; basilar length 42.5 (41.8-43.3); length of tooth-rows more than length of tympanic bulla; breadth of rostrum measured across lacrimal processes averaging more than a third of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth more than distance between last upper molar and jugular foramen.
Female (based on 2 adult topotypes and 2 adults and 4 subadults from central Alaska): See measurements and plates9-11. As described inMustela erminea richardsoniiexcept that: Weight, 1.5 (1.2-2.0) grams; basilar length, 35.7 (34.5-37.0); length of tooth-rows more than length of tympanic bulla; breadth of rostrum more than 30 per cent of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth more than distance between last upper molar and jugular foramen (except in specimens from Ellesmere Island where two distances are approximately equal).
Cranial differences fromMustela erminea kaneii(which occurs on the Asiatic side of Bering Strait), in both males and females, are: larger size relatively as well as actually, broader except in mastoidal region where relatively (to basilar length) the width is less; preorbital part of skull broader as well as longer.
Fromkadiacensisdifferences in the skull of the male are: size less; 13 per cent heavier, relatively (to basilar length) narrower across interorbital region and zygomatic arches; tympanic bullae relatively as well as actually narrower. Judging by the single available adult female ofkadiacensis, the skull of femalearcticais larger in all parts measured, a fourth heavier, has tympanic bullae of almost twice the volume and the interorbital and preorbital regions, relative to the braincase, are much reduced in whatever plane measured.
Differences fromrichardsonii, additional to those noted above in the formal description of the skull, between the males, are: larger in all parts measured except length of tympanic bulla which is about the same; 42 per cent heavier; relative to basilar length, skull broader with preorbital part longer as well as broader; tympanic bullae more inflated posteriorly. The same differences prevail between females except that the skull is 36 per cent heavier and inarcticathe length of the bulla is actually more (although relative to the basilar length less) and its greater inflation posteriorly is hardly perceptible. Differences fromalascensis, additional to those indicated in the formal descriptions of the skulls of the two, in males, are: larger in every part measured; 95 per cent heavier; relative to the basilar length, skull broader with preorbital part longer as well as broader; measured at a point opposite the foramen lacerum anterius, the width of the pterygoid space is more, rather than less, than 40 per cent of its length. Excepting this difference in width of interpterygoid space, the same differences prevail between females, those ofarcticabeing 56 per cent heavier.
Comparison withsempleiis made in the account of that subspecies.
Skull indistinguishable from that ofpolaris.
Remarks.—The person who studies specimens of this subspecies finds labels inscribed with the names of naturalists well known to all readers of literature on the Arctic. Sir John Franklin, R. McFarlane, R. Kennicott, E. W. Nelson and R. M. Anderson are names which appear commonly. Of Alaskan specimens prepared according to modern methods, a large share was obtained by O. J. Murie and L. R. Dice.
The ermine was observed in the far north by early explorers and was mentioned in the literature, almost always under the name then used for the ermine of northern Europe and Asia. In 1896 Bangs misapplied to it the namerichardsoniibut Merriam in the same year corrected the application of this name and proposed as new for this weasel the namearctica, the name in use today. For almost 50 years after Merriam and Bangs wrote about it,arcticawas treated, nominally at least, as a species distinct from its other relatives in both the Old- and New-World. The subspecific status ofarcticawas emphasized in 1944 (555) by the present writer in reporting in detail upon the specimens, ofMustela erminea, from Eastern Asia which were made available on loan by Professor B. S. Vinogradov and the late Anatol I. Argyropulo of the Leningrad Academy of Sciences. Specimens ofMustela erminea kaneiifrom the Asiatic side of Bering Strait andMustela erminea arcticafrom the American side are distinguishable by slight cranial characters but in coloration and external measurements I can detect no differences. Merriam's (1896:16) mention of more golden-colored upper parts and darker underparts in American specimens than inermineawas the result of his comparison of Alaskan and northern European specimens. When Old World specimens from eastern Siberia, instead of from Europe, are used the differences mentioned by Merriam do not apply. Incidentally, many Siberian specimens have the white border, on the ear, which Merriam (loc. cit.) noted as a distinguishing feature ofarctica. When Merriam namedarcticahe said (1896:15, 16) "Putorius arcticus. . . has heretofore been confounded withermineaorrichardsonii. . . . It is interesting to find in this country an Arctic circumpolar weasel which, though specifically distinct, is strictly the American representative of the Old Worlderminea." Bearing in mind that Merriam's concept of species and subspecies (see Merriam, 1919:6) differed from that of nearly all modern systematists it is clear from his statement quoted above that he correctly understood the zoölogical relationship obtaining between the ermines of the Old and New Worlds.
Ognev (1935:31) seems to have been the first to use the name combinationMustela erminea arcticafor Alaskan specimens. Thereby he expresses the view adopted here, namely that the American ermine is subspecifically but not specifically distinct from the Old World animal. Whether actual intergradation (crossbreeding) ever takes place across the narrow Bering Strait I do not know. I doubt that crossbreeding occurs but considering the Diomedes (islands), that might serve as a half way stopping point, and remembering Mr. Charles Brower's oral statement to me that he had seen tracks of ermine as far as 10 miles from the northern shore of Alaska out on the ice, the possibility must be granted of an occasional individual crossing from one side to the other of Bering Strait on the ice in winter or of being carried across when the ice broke up and drifted. If transfers of this kind occurred often one would expect ermines to occur also on Saint Lawrence Island where apparently they do not. The one skin (U. S. Nat. Mus. no. 259046) seen as labeled from there, my friend, Otto William Geist ascertained was imported as a skin with other furs from Siberia.
Ognev (op. cit.) who used the name combinationMustela erminea arcticafor Alaskan specimens, applied it also to animals from Kamchatka. At the same time he recognized the animal from the eastern mainland of Siberia (as opposed to the peninsula of Kamchatka) under the nameMustela erminea orientalisOgnev 1928. Hall (1944:556) applied the earlier proposed namePutorius kaneiiBaird 1857, to the animal on the eastern mainland of Asia and proposed the new nameMustela erminea dignafor the ermine of Kamchatka. In comparing material of these two Asiatic races with topotypes and other specimens ofM. e. arcticafrom Alaska, it seemed to me that the degree of relationship, one with the other, was about the same.M. e. dignahas a slightly larger preorbital region thanM. e. kaneii, and the skull is longer. In both of these particularsdignaapproaches closer toarctica.M. e. kaneiihas longer tympanic bullae and a wider skull thandignaand therein approaches more towardsarcticathan towarddigna. As nearly as I can make out,dignaandkaneiishow a nearly equal degree of resemblance toarctica. Also the degree of difference betweendignaandkaneiiis about the same as between either one of them andarctica. In view of the above considerations the ermines of the New and Old worlds are here regarded as only subspecifically distinct.
In the original description ofPutorius audax(here regarded as inseparable fromPutorius arcticusMerriam) Barrett-Hamilton erroneously designated the type locality as "Discovery Bay, North Greenland" whereas he should have written Grinnell Land [= Ellesmere Island of modern terminology] in place of Greenland. As reference to Nares (1877 and 1878) will readily reveal, Discovery Bay is near 65° W and 81° 40´ N, across Robeson Channel, to the west, from Greenland. The label on the type specimen and the specimen register in the British Museum of Natural History each designates the locality for this specimen, the type ofaudax, as Discovery Bay without mention of Greenland. The published accounts of Feilden (1878) and Nares (1877 and 1878) state that specimens of ermine were obtained at Discovery Bay. Probably H. C. Hart is the collector of the specimen; he was the naturalist attached to H. M. S. Discovery which wintered at Discovery Bay while H. W. Feilden was the naturalist attached to H. M. S. Alert which wintered a few miles southeast of Cape Sheridan, also on the eastern coast of Ellesmere Island.
It is true that from these ships a trip was made into Greenland and an ermine (only one individual it seems) was obtained there, but this individual was the type specimen ofMustela erminea polaris, in the account of which race something of the history of this specimen is given.
With the material available—and it is not entirely adequate—I can detect no features by which animals from the type locality ofaudaxcan be distinguished from typicalarcticawhich latter name has priority.
Intergradation withrichardsoniiprobably occurs completely across the continent. Intergrades here referred toarcticainclude those from Fort Goodhope. The one defective specimen from Lake Lebarge, Yukon, is not certainly identified asarcticaand how far west of Teslin Lake the boundary-line betweenarcticaandrichardsoniishould be drawn remains to be ascertained. The one specimen available from Hinchenbrook Island, no. 912 Mus. Vert. Zoöl., an adult female, is doubtfully referred toarcticabecause the damaged tympanic bullae appear to be no larger than inalascensis, and the size of the skull is more as inalascensisalthough intermediate between that race andarctica. Shape of the skull is more as inarctica. Possibly more nearly adequate material would show the existence on Hinchenbrook Island of an insular race differing in about the same degree fromarcticaof the mainland as does the insularkadiacensis. Nevertheless, the males from farther south at Cape Yakataga are in all respectsarcticaand this argues against near relationship toalascensisof the animal on Hinchenbrook Island. The three animals seen from Yakutat Bay are so young as not to display clearly the cranial characters of the subspecies but the extension of the color of the underparts onto the underside of the tail in them and also in the skin without corresponding skull from Glacier Bay, Alaska, is as inarctica, the race to which they are referred, and gives substantial basis for showing the geographic range ofarcticaas extending this far south along the Pacific Coast.
Specimens examined.—Total number, 281, arranged alphabetically by Districts and from north to south in each District. Unless otherwise indicated, specimens are in the collection of the United States National Museum.Alaska.Point Barrow, 22 (1[1], 1[2], 1[75], 4[1], 7[60], 6[74]); Flaxman Island, 3; Collinson Point, 1[77]; Salirochet River, 1[77]; Hulahula River, 1[2]; 69°20´ & 141°, 1; Rampart House, 1; Yukon River, mouth of Porcupine River, 18; Alatna River, 30 mi. from mouth, 1; Koyakuk Riv., 16 mi. below Bettles, 4; Shelton, 1[75]; Kruzamepa, 1[75]; Tanana, 6; Boulder Creek, Chena River, 3; Fort Reliance, 4; Yukon River, 20 miles above Circle, 2; Mts. near Eagle, 42 (1[60]); Snake River, Nome, 1[9]; Nulato, 3; No[e]wikakat Riv., 1; Kantishna, 3; Fairbanks, 5 (1 20 mi. E and 1 33 mi. E); Richardson, 1; N. Fk. Kuskokwim R. at base of Mt. Sischo, 1; N. Fk. Kuskokwim R. at Junction with McKinley Fk., 1; Nenana Riv., mouth of Maurice Cr., 1; Ober Cr., trib. of Jarvis Cr., Delta Riv. region, 1; head of Savage Riv., near Jennie Cr., 1; Wonder Lake, 1[74]; Bear Cr., 3; Unlakleet, 3; St. Michaels, 11; 125 mi. E and a little N of Knik, Cook Inlet, on S side Matanuska Range, 1[60]; Hope, Cook Inlet, 1; Iak Lake, 1[68]; head of Behring Riv., 1; Bethel, 2; Kenai Lake, 8; Kenai Peninsula, 13 (2[2]); He[i]nchenbrook Island, 1200 ft., 1[74]; Sunshine Point, Kaliekh River, Yakataga Dist., 1[8]; Cape Yakataga, 3[8]; Yakutat Bay, 3[74]; Seward, 7; Seldovia, 22 (4[2]); Homer, 1[2]; Cape Elizabeth, 18; Akchookuk Lake, 1; Lake Weelooluk, 1; Kokwok Riv., 80 mi. up, 4; Nushagak, 1; Nushagak Riv., 1; Kolukuk, 1; Egooshik River at mouth, 1; Glacier Bay, 1; Becharof Lake, between Portage Bay and Becharof Lake, 1; Ugashik Riv., 4; Chignik, 7; East base Frosty Peak, 1; Pavlov Bay, 1[100]; Mt. Pavlof, 1[75]; Unimak Island, 2 (1[75]).District of Franklin.Cape Sheridan, 1[2]; Discovery Bay, Ellesmere Island, 1[7](type specimen ofPutorius audaxBarrett-Hamilton); Axel Heiberg Island, 1[95]; Bache Peninsula, Ellesmere Island, 1[77]; Bedford Pims Island, 4[75]; Craig Harbor, 2[77]; Cape Kellett, Banks Island, 1[77]; Franklin Isthmus, 1[95]; King William Island, 2[95].District of Keewatin.Ualiak, Ogden Bay, 2[95].District of Mackenzie.Baillie Island, 1[75]; Franklin Bay, 1; Langton Bay, arm of Franklin Bay, 15 mi. S of, 1[2]; Cockburn Point, 69°N, 115°W, 2[77]; Dolphin and Union Strait, 1[77]; Bernard Harbor, 2[77]; Kent Peninsula, 4[95]; Horton Riv., near Fort Anderson, 1; Fort Anderson, 6; Anderson River, 3; Barry Island, Bathurst Inlet, 1[77]; Fort McPherson, 1; Peels River, 2; Arctic Red River, 8[75]; Fort Good Hope, 6; Clinton Colden, 1[2].Yukon.Kamarkak, 1[77]; Herschel Island, 1[75]; Lapierres House, 2; Forty Mile, L. T. Coal Cr., 4[74]; head of Coal Cr., 1; Macmillan River, Forks, 1; 20 mi. W. Ft. Selkirk, 1; Slims River, near Kluane, 1[75]; head of Lake Lebarge, 1.
Specimens examined.—Total number, 281, arranged alphabetically by Districts and from north to south in each District. Unless otherwise indicated, specimens are in the collection of the United States National Museum.
Alaska.Point Barrow, 22 (1[1], 1[2], 1[75], 4[1], 7[60], 6[74]); Flaxman Island, 3; Collinson Point, 1[77]; Salirochet River, 1[77]; Hulahula River, 1[2]; 69°20´ & 141°, 1; Rampart House, 1; Yukon River, mouth of Porcupine River, 18; Alatna River, 30 mi. from mouth, 1; Koyakuk Riv., 16 mi. below Bettles, 4; Shelton, 1[75]; Kruzamepa, 1[75]; Tanana, 6; Boulder Creek, Chena River, 3; Fort Reliance, 4; Yukon River, 20 miles above Circle, 2; Mts. near Eagle, 42 (1[60]); Snake River, Nome, 1[9]; Nulato, 3; No[e]wikakat Riv., 1; Kantishna, 3; Fairbanks, 5 (1 20 mi. E and 1 33 mi. E); Richardson, 1; N. Fk. Kuskokwim R. at base of Mt. Sischo, 1; N. Fk. Kuskokwim R. at Junction with McKinley Fk., 1; Nenana Riv., mouth of Maurice Cr., 1; Ober Cr., trib. of Jarvis Cr., Delta Riv. region, 1; head of Savage Riv., near Jennie Cr., 1; Wonder Lake, 1[74]; Bear Cr., 3; Unlakleet, 3; St. Michaels, 11; 125 mi. E and a little N of Knik, Cook Inlet, on S side Matanuska Range, 1[60]; Hope, Cook Inlet, 1; Iak Lake, 1[68]; head of Behring Riv., 1; Bethel, 2; Kenai Lake, 8; Kenai Peninsula, 13 (2[2]); He[i]nchenbrook Island, 1200 ft., 1[74]; Sunshine Point, Kaliekh River, Yakataga Dist., 1[8]; Cape Yakataga, 3[8]; Yakutat Bay, 3[74]; Seward, 7; Seldovia, 22 (4[2]); Homer, 1[2]; Cape Elizabeth, 18; Akchookuk Lake, 1; Lake Weelooluk, 1; Kokwok Riv., 80 mi. up, 4; Nushagak, 1; Nushagak Riv., 1; Kolukuk, 1; Egooshik River at mouth, 1; Glacier Bay, 1; Becharof Lake, between Portage Bay and Becharof Lake, 1; Ugashik Riv., 4; Chignik, 7; East base Frosty Peak, 1; Pavlov Bay, 1[100]; Mt. Pavlof, 1[75]; Unimak Island, 2 (1[75]).
District of Franklin.Cape Sheridan, 1[2]; Discovery Bay, Ellesmere Island, 1[7](type specimen ofPutorius audaxBarrett-Hamilton); Axel Heiberg Island, 1[95]; Bache Peninsula, Ellesmere Island, 1[77]; Bedford Pims Island, 4[75]; Craig Harbor, 2[77]; Cape Kellett, Banks Island, 1[77]; Franklin Isthmus, 1[95]; King William Island, 2[95].
District of Keewatin.Ualiak, Ogden Bay, 2[95].
District of Mackenzie.Baillie Island, 1[75]; Franklin Bay, 1; Langton Bay, arm of Franklin Bay, 15 mi. S of, 1[2]; Cockburn Point, 69°N, 115°W, 2[77]; Dolphin and Union Strait, 1[77]; Bernard Harbor, 2[77]; Kent Peninsula, 4[95]; Horton Riv., near Fort Anderson, 1; Fort Anderson, 6; Anderson River, 3; Barry Island, Bathurst Inlet, 1[77]; Fort McPherson, 1; Peels River, 2; Arctic Red River, 8[75]; Fort Good Hope, 6; Clinton Colden, 1[2].
Yukon.Kamarkak, 1[77]; Herschel Island, 1[75]; Lapierres House, 2; Forty Mile, L. T. Coal Cr., 4[74]; head of Coal Cr., 1; Macmillan River, Forks, 1; 20 mi. W. Ft. Selkirk, 1; Slims River, near Kluane, 1[75]; head of Lake Lebarge, 1.
Ermine
Putorius arcticus polarisBarrett-Hamilton, Ann. and Mag. Nat. Hist., 13 (ser. 7):393, May, 1904.Mustela erminea, Manniche, Meddelelser om Grønland, 45:80-85, 1 fig., 1910.Mustela arctica polaris, Miller, U. S. Nat. Mus. Bull., 79:97, December 31, 1912.Mustela erminea polaris, Hall, Journ. Mamm., 26:179, July 19, 1945.
Putorius arcticus polarisBarrett-Hamilton, Ann. and Mag. Nat. Hist., 13 (ser. 7):393, May, 1904.
Mustela erminea, Manniche, Meddelelser om Grønland, 45:80-85, 1 fig., 1910.
Mustela arctica polaris, Miller, U. S. Nat. Mus. Bull., 79:97, December 31, 1912.
Mustela erminea polaris, Hall, Journ. Mamm., 26:179, July 19, 1945.
Type.—Probably female, skin only; no. 78. 6. 19. 11, Brit. Mus. Nat. Hist.; Gap Valley, 7-1/4 miles northeast Cape Brevoort, 82° N, 59° 20´ W, Northwestern Greenland; June 15 or 16, 1876; obtained by Lewis A. Beaumont.The skin is in full, fresh summer pelage, fairly well stuffed except for the tail which is unstuffed; the whole is in a good state of preservation.Range.—North coast, and east coast as far south as Turner Sound (between 69 and 70 degrees) of Greenland. See figure25on page95.Characters for ready recognition.—Differs fromM. e. arcticain lighter upper parts (near [j] Buckthorn Brown rather than Raw Umber or darker) and more intensely-colored underparts that are Buff Yellow rather than Sulphur Yellow, Colonial Buff, or Primrose Yellow; fromM. e. sempleiin color in same fashion as fromarcticaand in larger size of skull.Description.—Size.—Male: One subadult and two adults (one ad. from Scøresby Sound and other two from Ymer Island) measure as follows, the average being given first: Total length, 318 (301, 320, 315); length of tail, 72 (69, 70, 73); length of hind foot, 46.5 (44, 46, 47).Female: No measurements taken in the flesh available but hind foot, measuring 33.5 in the dried state and therefore approximately 35 in life.Color.—As described inMustela erminea arcticaexcept that upper parts in summer near (j) Buckthorn Brown and tone 4 of Dark Fawn of plate 307 to tone 1 of Raw Umber of plate 301 of Oberthür and Dauthenay. Underparts Buff-Yellow. Least width of color of underparts averaging, in 3 males, 66 (57-72) per cent of greatest width of color of upper parts. Black tip of tail in same males averaging 71 (70-72) mm. which is 99 (99-104) per cent of length of tail-vertebrae.The lighter-colored upper parts and more intensely yellow underparts are the distinguishing features of the subspeciespolarisin comparison with other races of AmericanM. erminea.Skull.—Male (based on 5 adults from eastern Greenland): See measurements. As described inMustela erminea richardsoniiexcept that: Weight more (not recorded); basilar length, 41.3 (39.0-42.4); length of tooth-rows more than length of tympanic bulla; breadth of rostrum measured across lacrimal processes averaging more than a third of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth more than distance between last upper molar and jugular foramen.Female (based on 2 adults, Turner Sund and Kap Hoeg): See measurements. As described inMustela erminea arcticaexcept that basilar length 36.8 (35.9, 37.8), and length of tooth-rows not more than length of tympanic bulla. Skulls of females not in hand when this comparison is written; only the recorded measurements are available.
Type.—Probably female, skin only; no. 78. 6. 19. 11, Brit. Mus. Nat. Hist.; Gap Valley, 7-1/4 miles northeast Cape Brevoort, 82° N, 59° 20´ W, Northwestern Greenland; June 15 or 16, 1876; obtained by Lewis A. Beaumont.
The skin is in full, fresh summer pelage, fairly well stuffed except for the tail which is unstuffed; the whole is in a good state of preservation.
Range.—North coast, and east coast as far south as Turner Sound (between 69 and 70 degrees) of Greenland. See figure25on page95.
Characters for ready recognition.—Differs fromM. e. arcticain lighter upper parts (near [j] Buckthorn Brown rather than Raw Umber or darker) and more intensely-colored underparts that are Buff Yellow rather than Sulphur Yellow, Colonial Buff, or Primrose Yellow; fromM. e. sempleiin color in same fashion as fromarcticaand in larger size of skull.
Description.—Size.—Male: One subadult and two adults (one ad. from Scøresby Sound and other two from Ymer Island) measure as follows, the average being given first: Total length, 318 (301, 320, 315); length of tail, 72 (69, 70, 73); length of hind foot, 46.5 (44, 46, 47).
Female: No measurements taken in the flesh available but hind foot, measuring 33.5 in the dried state and therefore approximately 35 in life.
Color.—As described inMustela erminea arcticaexcept that upper parts in summer near (j) Buckthorn Brown and tone 4 of Dark Fawn of plate 307 to tone 1 of Raw Umber of plate 301 of Oberthür and Dauthenay. Underparts Buff-Yellow. Least width of color of underparts averaging, in 3 males, 66 (57-72) per cent of greatest width of color of upper parts. Black tip of tail in same males averaging 71 (70-72) mm. which is 99 (99-104) per cent of length of tail-vertebrae.
The lighter-colored upper parts and more intensely yellow underparts are the distinguishing features of the subspeciespolarisin comparison with other races of AmericanM. erminea.
Skull.—Male (based on 5 adults from eastern Greenland): See measurements. As described inMustela erminea richardsoniiexcept that: Weight more (not recorded); basilar length, 41.3 (39.0-42.4); length of tooth-rows more than length of tympanic bulla; breadth of rostrum measured across lacrimal processes averaging more than a third of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth more than distance between last upper molar and jugular foramen.
Female (based on 2 adults, Turner Sund and Kap Hoeg): See measurements. As described inMustela erminea arcticaexcept that basilar length 36.8 (35.9, 37.8), and length of tooth-rows not more than length of tympanic bulla. Skulls of females not in hand when this comparison is written; only the recorded measurements are available.
To me the skull ofpolarisis indistinguishable from that ofarctica. Therefore the comparisons made of the skull ofarcticawith those of other subspecies will apply also forpolaris.
Remarks.—In view of the heretofore erroneous assignment of the type locality ofMustela erminea audaxto Greenland, pains were taken to verify the statement by Barrett-Hamilton (1904:393) relative to the type specimen ofpolaris. Taking pains thus seemed the more worthwhile because in the specimen register at the British Museum of Natural History, there is written to the right of catalogue numbers 78-6 = 19 nos. 1-11, "Discovery Bay Presented by Mr. Hart Arctic Collection." This refers to no. 78.6.19.1. There are no ditto marks below but by implication this data applies also to nos. 1-11, which include the holotype ofpolaris. A label attached to the specimen does however give the locality as "Hall Land" "N Greenland" and another label has on it "Ermine, procured by Mr. Beaumont Greenland Lat 89° Long W 59-20." The 89° is obviously a mistake (on the label or in my transcription of it) for 82°.
Reference to Nares (1877:385) reveals that Lieutenant Lewis A. Beaumont, under date of June 15 and 16, 1876, wrote in his field journal as follows: "I shot an ermine." In the daily accounts of his journey from Discovery Bay on Grinnell Land [= Ellesmere Island], across Robeson Channel and along the north coast of Greenland to the west base of Mount Farragut near 50° 30´ W he mentions the ermine only this once. For several other kinds of animals, Beaumont mentions individuals seen or shot, often with the notation that this is the second, or third seen. This mention of a kind of animal whenever seen was in accordance with orders. On page39of the Discovery Report (op. cit., 1877) in "General orders to sledging parties" by Captain G. S. Nares, Commanding the Expedition, we find ". . . note daily: IV State the animals seen and those shot." Reference to the map facing page358of the (op. cit.) report reveals that on the 15th and 16th, camps were made by Beaumont in Gap Valley, each 7-3/4 miles northeast of Cape Brevoort, one camp on either side of the 82° line, and separated from each other by a distance of only 2-1/4 air line miles or 4-1/2 miles march according to his journal.
These several data, then, are the bases for designating the type locality ofM. e. polaris, in the way that I have stated it at the beginning of this account of the subspecies.
The light-colored upper parts and more intensely yellow underparts well differentiate this subspecies fromarcticaorsemplei. Intergradation is suggested by a skin, no. 1462, Copenhagen Zoological Museum, from Axel Heibergs Land, the color of the underparts of which agrees with that of specimens from Greenland. Also the color of the upper parts is decidedly nearer that of animals from Greenland than to that of specimens from Ponds Inlet, Tulican and Gifford River. No other specimens west or south of Greenland suggest intergradation. In Greenland itself, one adult, a female from Turner Sund, East Greenland, has the underparts no more yellowish than in some specimens from Melville Peninsula. This female is darker on the back than any one of the other 10 specimens from Greenland in summer pelage examined at the same time, but even so is not so dark colored as animals from Baffin Island or other islands to the west of Greenland.
The final summation of information about this subspecies would have been more precise if I had been able to have actually in hand, at the time of writing, specimens preserved in the Copenhagen Zoological Museum. The war made it impractical to secure the loan of these as previously planned. Even so, the measurements and notes on color that I obtained from this material, in 1937, in Copenhagen, suffice to prove that the subspeciespolarisis well set off in color from the other American subspecies ofMustela erminea.
The best material of this subspecies is in the University Zoological Museum at Copenhagen, Denmark.
Specimens examined.—Total number, 35, arranged by locality from the western end of the north coast of Greenland, eastward and then southward down the east coast. Unless otherwise indicated, specimens are in the Universitetets Zoologisk Museum, Købnhavn, Danmark.Gap Valley, 7-1/4 mi. NE Cape Brevoort, 82° N, 59° 20´ W, 1 (British Mus.); Dragon Point, 1; Danmarks Havn (Fjeldene ved Baadskjeret, 1; lille Fjeld, 1; Lyservig, 1; harefjeldets, 4; Rypefjeldet, 1; Baadskjeret, 1; Danmarkshavn, 3) 12; Christians Havn, 1 (not found on map); Shannon Island, 4; Germania Havn, 2; Claveringoen, 1; Carls Havn, 1; Myggbukta, 2 (British Mus.); Ymer[s] Island, 2 (Mus. Comp. Zool.); Kap Hoegh, Jamesonsland, 1 (Berlin Zool. Mus.); Scoresby Sund, 3; Turner Sund, 4.
Specimens examined.—Total number, 35, arranged by locality from the western end of the north coast of Greenland, eastward and then southward down the east coast. Unless otherwise indicated, specimens are in the Universitetets Zoologisk Museum, Købnhavn, Danmark.
Gap Valley, 7-1/4 mi. NE Cape Brevoort, 82° N, 59° 20´ W, 1 (British Mus.); Dragon Point, 1; Danmarks Havn (Fjeldene ved Baadskjeret, 1; lille Fjeld, 1; Lyservig, 1; harefjeldets, 4; Rypefjeldet, 1; Baadskjeret, 1; Danmarkshavn, 3) 12; Christians Havn, 1 (not found on map); Shannon Island, 4; Germania Havn, 2; Claveringoen, 1; Carls Havn, 1; Myggbukta, 2 (British Mus.); Ymer[s] Island, 2 (Mus. Comp. Zool.); Kap Hoegh, Jamesonsland, 1 (Berlin Zool. Mus.); Scoresby Sund, 3; Turner Sund, 4.
Ermine
Plates2,3,4,9,10and11
Mustela arctica sempleiSutton and Hamilton, Ann. Carnegie Mus., 21:79, February 13, 1932.Mustela arctica labiataDegerbøl, Rept. 5th Thule Exped., 2 (no. 4):25, 1935, type from Malugsitaq, Melville Peninsula, Canada.Mustela erminea semplei, Hall, Journ. Mamm., 26:179, July 19, 1945.
Mustela arctica sempleiSutton and Hamilton, Ann. Carnegie Mus., 21:79, February 13, 1932.
Mustela arctica labiataDegerbøl, Rept. 5th Thule Exped., 2 (no. 4):25, 1935, type from Malugsitaq, Melville Peninsula, Canada.
Mustela erminea semplei, Hall, Journ. Mamm., 26:179, July 19, 1945.
Type.—Male, subadult, skull and skin; no. 6470, Carnegie Mus.; Coral Inlet, South Bay, Southampton Island, Canada; October 8, 1929; obtained by George Miksch Sutton, original no. 3M.The skull has two holes in it: one is immediately above the left canine, and the other (2 × 5.5 mm.) is 3 millimeters to the left of the median line at the juncture of the frontal and parietal bones. From this last mentioned hole a fracture extends back halfway to the lambdoidal crest. The tip of the left upper canine is broken off. Otherwise the skull is complete, and the teeth all are present and entire. The skin is well made and in fresh white winter pelage except for a trace of the old brown summer pelage on the back, on the tail, on the anterior borders of the ears, and in a spot 11 mm. long and 8 mm. wide on the nose.Range.—Baffin and Southampton islands, Melville Peninsula and west side of Hudsons Bay as far south as Eskimo Point. See figure 25 on page95.Characters for ready recognition.—Differs fromM. e. arctica, in that, in males, hind foot less than 44 and basilar length less than 41 and in that females average smaller, their skulls being only about 10 per cent lighter; fromM. e. polarisin darker upper parts (Raw Umber rather than Buckthorn Brown) and less-intensely-colored underparts that are Sulphur Yellow, Colonial Buff or Primrose Yellow rather than Buff Yellow, and in lesser size in the same fashion as fromarctica; fromM. e. richardsonii, of both sexes, in that proximal two-thirds of under side of tail colored same as underparts rather than same as upper parts and by least interorbital breadth amounting to more, instead of less, than distance between glenoid fossa and posterior border of external auditory meatus.Description.—Size.—Male: Ten adults and subadults, from Southampton Island, yield average and extreme measurements as follows: Total length, 282 (267-318); length of tail, 77 (59-87); length of hind foot, 40 (38-43).Female: Four subadults from Southampton Island yield average and extreme measurements as follows: Total length, 271 (256-288); length of tail, 71 (69-74); length of hind foot, 35 (33-38).Color.—As described inM. e. arcticaexcept that least width of color of underparts averaging, in 7 males, 59 (45-81) per cent of greatest width of color of upper parts. Black tip of tail in 19 male topotypes averaging 72 (64-83) mm. which is 91 (75-122) per cent of length of tail-vertebrae.Skull.—Male (based on 2 adults and 10 subadults from Southampton Island): See measurements and plates2-4. As described inMustela erminea richardsoniiexcept that: Weight, 2.0 (in one subadult) grams; basilar length, 37.5 (35.7-39.9); length of tooth-rows more than length of tympanic bulla; breadth of rostrum more than a third of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth more than distance between last upper molar and jugular foramen.Female (based on 1 adult and 4 subadults from Southampton Island): See measurements and plates9-11. As described inMustela erminea richardsoniiexcept that: Weight, 1.35 (in one adult) grams; basilar length, 34.2; breadth of rostrum more than 30 per cent of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth more or less than (approximately same as) distance between last upper molar and jugular foramen.
Type.—Male, subadult, skull and skin; no. 6470, Carnegie Mus.; Coral Inlet, South Bay, Southampton Island, Canada; October 8, 1929; obtained by George Miksch Sutton, original no. 3M.
The skull has two holes in it: one is immediately above the left canine, and the other (2 × 5.5 mm.) is 3 millimeters to the left of the median line at the juncture of the frontal and parietal bones. From this last mentioned hole a fracture extends back halfway to the lambdoidal crest. The tip of the left upper canine is broken off. Otherwise the skull is complete, and the teeth all are present and entire. The skin is well made and in fresh white winter pelage except for a trace of the old brown summer pelage on the back, on the tail, on the anterior borders of the ears, and in a spot 11 mm. long and 8 mm. wide on the nose.
Range.—Baffin and Southampton islands, Melville Peninsula and west side of Hudsons Bay as far south as Eskimo Point. See figure 25 on page95.
Characters for ready recognition.—Differs fromM. e. arctica, in that, in males, hind foot less than 44 and basilar length less than 41 and in that females average smaller, their skulls being only about 10 per cent lighter; fromM. e. polarisin darker upper parts (Raw Umber rather than Buckthorn Brown) and less-intensely-colored underparts that are Sulphur Yellow, Colonial Buff or Primrose Yellow rather than Buff Yellow, and in lesser size in the same fashion as fromarctica; fromM. e. richardsonii, of both sexes, in that proximal two-thirds of under side of tail colored same as underparts rather than same as upper parts and by least interorbital breadth amounting to more, instead of less, than distance between glenoid fossa and posterior border of external auditory meatus.
Description.—Size.—Male: Ten adults and subadults, from Southampton Island, yield average and extreme measurements as follows: Total length, 282 (267-318); length of tail, 77 (59-87); length of hind foot, 40 (38-43).
Female: Four subadults from Southampton Island yield average and extreme measurements as follows: Total length, 271 (256-288); length of tail, 71 (69-74); length of hind foot, 35 (33-38).
Color.—As described inM. e. arcticaexcept that least width of color of underparts averaging, in 7 males, 59 (45-81) per cent of greatest width of color of upper parts. Black tip of tail in 19 male topotypes averaging 72 (64-83) mm. which is 91 (75-122) per cent of length of tail-vertebrae.
Skull.—Male (based on 2 adults and 10 subadults from Southampton Island): See measurements and plates2-4. As described inMustela erminea richardsoniiexcept that: Weight, 2.0 (in one subadult) grams; basilar length, 37.5 (35.7-39.9); length of tooth-rows more than length of tympanic bulla; breadth of rostrum more than a third of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth more than distance between last upper molar and jugular foramen.
Female (based on 1 adult and 4 subadults from Southampton Island): See measurements and plates9-11. As described inMustela erminea richardsoniiexcept that: Weight, 1.35 (in one adult) grams; basilar length, 34.2; breadth of rostrum more than 30 per cent of basilar length; interorbital breadth more than distance between glenoid fossa and posterior border of external auditory meatus; zygomatic breadth more or less than (approximately same as) distance between last upper molar and jugular foramen.