4 NORTH AMERICAN MUSTELID^. 



Skull with the paroccipital process uot closely applied to the audi- 

 tory bulla; the mastoid process promiuoat and projecting out- 

 wards or downwards behind the external auditory meatus; ex- 

 ternal auditory meatus diversiform. Intestinal canal with no 

 Ciocura. Prostate gland not salient, being contained in the 

 thickened walls of the urethra. Skull with the carotid canal 

 distinct, and more or less in advance of the foramen lacerum 

 posticum; condyloid foramen alone distinct from the foramen 

 lacerum posticum; glenoid foramen generally well defined. Os 

 penis very large. Cowper's glands not developed. 



(Super-family) Arctoidea. 



True molars of upper jaw^ one (M. ^ : rarely — in MelUvonn(B—j)', 

 last premolar of upper jaw sectorial (rarely — in Enhydrince — 

 with blunt tubercles) (Family) Mustelidce. 



DIVISION OF THE MUSTELID.E INTO SUBFAMILIES. 



Haviug thus, by a process of gradual elimination of the char- 

 acters of other groups, reached a family, Mustelidce^ we may 

 proceed to inquire of what subdivisions the family itself is 

 susceptible. Authors — sven throwing the older writers out of 

 consideration — differ greatly in their methods of reckoning the 

 subfamilies and genera, the number of subfamilies recognized 

 varying from three or four to eight. According to my present 

 understanding of the subject, derived from my knowledge of 

 American forms, I am inclined to consider that, if any sub- 

 family divisions are to be adopted, regard for equivalency, or 

 the just coordination of the characters involved, requires a 

 larger number of subfamilies than have usually been recog- 

 nized — very possibly the full number, eight, admitted by Dr. 

 Gill. The excellent analysis of the family given by this writer 

 (see p. 3, note) is herewith presented : — 



XVI. — MUSTEL1D.E. 



Suh-families. 



I. Skull with the cerebral portion comparatively compressed backwards ; and 

 with the rostral portion comparatively produced, attenuated, and 

 transversely conv^ex above ; ant'eorbital foramen small and opening 

 forwards. Feet with little developed or no interdigital membrane 

 [and the species, with few exceptions, not aquatic]. 

 A. Auditory bulla much inflated, undivided, bulging, and convex forwards ; 

 periotic region extending little outwards or backwards. Palate 

 moderately emarginated. 



