1885.] BR. ST. G. MIVART ON THE ARCTOIDEA. 393 



a doubtful problem. It has the number of true molar teeth and the 

 external form of the Bears, but it is less plantigrade. The cou- 

 dyloid foramina are minute instead of very large, and the basiocci- 

 pital has the depressions separated by a crest, as in the B^ulgers, 

 instead of being flat and wide, as in the Bears ; and the bulla, instead 

 of being wide and flattened, is slightly swollen out, but very small, 

 as inAilurus. Then there is no alisphenoid canal ; while the glenoid 

 foramen, so conspicuous in the Bears, is hidden at the bottom of a 

 large notch between the bulla and the zygoma. The general form 

 of the mandible also is much more like that of Ailurus than of Ursus. 

 There is a fundamental resemblance also between the crowns of the 

 teeth in Ailurus and Ailuropus, in spite of their exaggerated cha- 

 racter iu the latter genus ; so that on the whole it appears to me 

 that there is a more decided natural affinity between Ailuropus and 

 Ailurus than between Ailuropus and Ursus. 



The Weasels and their allies seem to be specially predacious 

 variations of the Badger type ; and I have no reason to urge (beyond 

 the structure of the kidney) against the generally received view that 

 the Otters are aquatic variations of the same type. 



There will thus be three families, Procyonid^, Mustelid^, 

 and Ursid.e. The first of these is plainly subdivisible into two sub- 

 famihes — (1) ProcyoniticB, and (2) AilurincB; while I agree with 

 Professor Flower in dividing the Mustelid^ into the three sub- 

 families — (1) Melince, (2) Mustelince, and (3) Lutrince. 



These subdivisions may be synoptically characterized as follows : — 



Fam. I. PROCYONIDiE. 

 Kidneys simple. True molars 7, or 5, obtusely tuberculated. 



Dentition not sectorial. Alisphenoid canal present or absent. 

 Hub. America or Asia. 



Subfamily 1. Procyonin^. 

 True molars g. No alisphenoid canal. Molars not very com- 

 plexly tuberculated. 

 Hub. America. 



Procyon. JBassaris. Cercoleptes. 



Nasua. Bassarici/on, 



Subfamily 2. AiluriNjE. 

 True molars g with an alisphenoid canal, or 3 without an ali- 

 sphenoid canal. Molars very complexly tuberculate. 

 Hab. Eastern Asia. 



Ailunts. Aihcropus. 



Fam. II. MUSTELID.E. 



Kidneys mostly simple. True molars g or ^. Teeth tuberculate 

 or sectorial. No alisphenoid canal. 

 Hab. Old and New Worlds. 



