116 NORTH AMERICAN MUSTELID.E. 



yote OH the skull and teeth. 



Skull and teeth. — A descriptiou of the crauiuni and dentition 

 of this typical species will auswer well for that of the subgenus 

 Gale (see p. 99). The skull, though strong, is smooth in its gen- 

 eral superficies, lacking almost entirely the sagittal ridge and 

 roughness of muscular attachment which characterize the crania 

 of the larger lorms, like fectidus and vlson for instance. The 

 forehead is turgid and convex in prolile ; the muzzle very short, 

 swollen, and nearly vertically truncate. The zygomata are very 

 slender, regularly arched throughout; the anterior root is a 

 thin llaring plate, perforated by a large foramen anteorbitale. 

 The cranium proper is peculiarly cylindrical rather than ovoidal; 

 the postorbital constriction is abrupt, though slight. Supra- 

 orbital processes are moderately developed. The palatal emar- 

 gination is slight; the pterygoids send out a spur to embrace 

 the adjacent foramen, and terminate roundly, without a hamu- 

 iar process, so conspicuous in the larger Pw^orii and in Mustela, 

 or with only a slight one. The bulhe auditorial are very large, 

 llattish, i)arallel rather than divergent, and not in the least 

 produced into a tubular meatus; on the contrary, the orifice of 

 the meatus shows from below as an emargination. The glen- 

 oid fossic have so prominent a hinder edge that they seem to 

 l)resent forward rather than downward. 



The teeth scarcely furnish occasion for remark, as they pre- 

 sent no peculiarities. In a specimen before me, the middle 

 upper premolar of the right side has failed to develop. This 

 is rather a large tooth to thus abort. Among the incisors 

 (much as elsewhere in this subfamily), various irregularities are 

 observable in different specimens, owing to the crowded state 

 of. these small teeth. (For cranial and dental peculiarities as 

 compared with longicauda, see beyond.) 



Description of the external characters. 



A general description of this animal, herewith given, neces- 

 sarily embraces many points shared with its congeners. It ma^^ 

 be taken in amplification of the generic characters already 

 given, and serve as a standard of comparison for other species, 

 in the several accounts of which a repetition of non-essential 

 specific characters is by this means avoided. 



In general form, the Stoat typifies a group of carnivorous 

 Mammals aptly called ' vermiform ', in consideration of the ex- 

 treme length, tenuity and mobility of the trunk, and shortness 



