1902.] NATURAL SCIENCES OF PHILADELPHIA. 449 



skull of hrumalis figured by him is smaller than the largest speci- 

 men I have, so that the differences Osgood seeks to draw between 

 the two in this regard are much less than Avould appear. The 

 relative size of the audita! bulloj in actuosa and brumalis, where 

 skulls of same size are compared, is so nearly the same as to make 

 them of no diagnostic value, and the heaviness of dentition falls 

 under the same restrictions. Taking these two races of americana 

 and contrasting them therewith, the Pennsylvania and Maine speci- 

 mens show an extreme diminution of size, being about 10 mm. 

 shorter and relatively somewhat narrower than the northern races ; 

 but we are unable to make these differences in size, great as they 

 appear, of specific value, for the martens from the north shore of 

 Lake Superior and from Tobique and Trousers lake. New Bruns- 

 wick, are plainly intermediate and counectant in cranial characters, 

 measuring only 5 to 6 mm. shorter than the largest skulls of actuosa 

 and brumalis. No doubt skulls from western Labrador and Kee- 

 watiu would complete the chain of gradation thus indicated. It 

 may be remarked that the development of sagittal crest in actuosa 

 and hrumalis, and the postei'ior angularity and expansion of their 

 zygomse, are more or less in excess of any specimens of the southern 

 animal ; but an examination of the cuspidatiou, size and outline of 

 the teeth in all the forms except caurlna shows that so-called differ- 

 ences are confined to individual variation, as proved by the 

 unusually large series of crania now in hand. In color, brumalis is 

 separable from any other eastern interior form on account of its 

 dark shades. In the male specimen from Okak there is a close re- 

 semblance to the specimen from Sullivan county, Penna., both in tint 

 and pattern of coloration, the difference consisting almost solely in 

 the greater length of the coarser long hairs of the over fur. Tliese 

 are also blacker and the median (subapical) shade of upper back, 

 sides and rump is less fulvous. The color of the under fur is a 

 shade darker ash than that of the Pennsylvania specimens. In the 

 female Okak specimen the whole body colors are much darker than 

 in the male, being a blackish chocolate, and the fulvous cast of 

 under fur seen in the male is replaced by a cinnamon or bistre 

 shade in the female. In both, the head is lighter than the body. 

 As compared with actuosa the Labrador form is nuicli darker, 

 Mackenzie river actuosa being characterized from all others by the 

 contrast of their light- hued sides and heads with the darkly cou- 

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