In comparison with richardsonii, the skulls of males averaged smaller in every measurement taken except breadth of rostrum and interorbital breadth which are more, and zygomatic breadth and length of inner lobe of M1 which are approximately the same; skull about 20 per cent lighter; in relation to basilar length, preorbital region longer and broader in every part measured. Female averages larger, in every part measured; 23 per cent heavier; in relation to basilar length, every other measurement more. It is noteworthy that the skull of the male is smaller and the skull of the female larger than in richardsonii.
Differences from arctica are: Size less, in each sex; males about 40 per cent and females 10 per cent lighter; in males, skull more rounded in outline as viewed from above because zygomatic arches arise less abruptly from skull; in males tympanic bullae do not project so far ventrally from squamosal floor of braincase; with these exceptions, skull of semplei can be said to be a smaller edition of that of arctica.
From polaris, semplei differs, cranially, in the same way as from arctica.
Remarks.—There is a slight increase in size of ermines toward the north which probably is the result of intergradation between semplei and arctica. Specimens from the northern part of Baffin Island are larger than those from farther south. Specimens from the mainland west of Southampton Island may owe their smaller (than in arctica) size to intergradation with richardsonii almost as much as to intergradation with semplei.
Degerbøl's name Mustela arctica labiata was applied to specimens, which to me are indistinguishable from topotypes of Mustela arctica semplei, which latter name has three years priority. Degerbøl (1935:34) states that Malugsitaq, Melville Peninsula, is the type locality. He did not designate a type specimen. Reference to his account (op. cit.:26) shows that he lists five specimens from the type locality, or more precisely as "Malugsitaq, Lyon Inlet. 5 summer skins. ♂ ♂ June-July 1922. P. F., CN. 2262-2266." On labels attached to these specimens, "Lyon Inlet" is replaced with "Melville Peninsula." On July 28, 1937, Degerbøl and I together examined these specimens in his laboratory. Because no. 2262 is first mentioned I regard it as the type. It is a juvenal male, skull and skin, no. 2262 (20.5 1931.8), Univ. Zool. Mus. Copenhagen, obtained in June or July of 1922 by Peter Freuchen whose original number was / s 2324. The specimen is one of 5 males taken at the same locality by the same collector and they bear identical data as to date. They look to be of the same litter for all are roughly of the same size and each retains milk teeth.
Additional females, with external measurements carefully taken, are much needed from Southampton Island, because the available females are insufficient to show the degree of sexual dimorphism. If the meager data available be accepted, the difference in size between the two sexes is less than in other subspecies. My own feeling is that a better sample of females would show the secondary sexual difference in size to be more than available data indicate.
Specimens examined.—Total number, 183, arranged from north to south by islands, or regions attached to the mainland, and from north to south in each region or island. Unless otherwise indicated, specimens are in the Zoological Museum, University of Copenhagen, Denmark.
Baffin Island. Pond
Inlet, 8; (5[77]); Tulukan (sometimes spelled Tulukat), 6; Cape Eglinton, 1[7]; Gifford River, 2; Clyde, 3[86]; head of Cumberland Sound, 1[91]; Pangnirtung, 2[77]; Kingnait Fiord, 1[91]; Kikkulin Island, Cumberland Sound, 1[7]; Blacklead Island, Cumberland Gulf, 1; merely Cumberland Gulf, 1[7]; merely east Baffin Island, 34[7]; Cape Dorset, 2[2]; SW coast of Baffin Island, 1[75].Melville Peninsula. Iglulik, 3; Pingerqalik, 2; Kingadjuaq, Amitsog, 3; Rae Isthmus, 3; Lyons Inlet, 13(9[2]); M[N?] alugsitaq, Lyon Inlet, 5; Itibdjeriang, 2; Repulse Bay, 27 (22[2], 2[19]); Drichetts Cove, Hurd Channel, 1[2]; Gore Bay, 1; Haviland Bay, 1; Cleveland Harbor, Frozen Strait, 1.
Southampton Island and adjacent islands. Danish Island, 11; Vansittart Island, 4. Southampton Island: Coral Inlet, 19 (1[77], 18[9]); Prairie Point, 1[9]; Munnimunnek Point, South Bay, 5[9]; Native Point, 1[9]; Ranger Rim, 1[9]; Koodloatok (not found on map), 1[77]; merely Southampton Island, 1[77]; Gore Bay, 1[2]; Fox Channel, 2[2].
Mainland to west of Southampton Island. Cape Fullerton, 3 (1[77], 2[2]); Chesterfield Inlet, 4 (1[77], 1[9]); Tavane, 1[77]; N of Wagner Inlet, 1; Eskimo Point, 1[86].