1885.] DR. ST. G. MIVART ON THE ARCTOIDEA. 343 



point where it doubles, tlirough the cartilage covering the foramen 

 lacerum anterius. 



" The modifications of the bulla mostly depend on the size of the 

 species, it being much more swollen in the smaller ones ; the mastoid 

 and paroccipital processes are also developed in relation to the dimen- 

 sions of the species, or even the age of the individual ; in the 

 smallest species they have hardly any projection, while in the larger 

 ones they show the same essential structure as iu the Bears. 



" Among the characters which I have pointed out iu the base of 

 the cranium, it will be seen that the only tangible distinction be- 

 tweeu the Bears and the Weasels is the presence of the alisjihenoid 

 canal in the former, and its constant absence in tlie latter. Much 

 as I have iusisted upon the importance of this character as assisting 

 to distinguish groups, I do not consider it sufficient alone to entitle 

 the groups which it separates to the rank of families ; neither am I 

 prepared to admit the difference of the teeth sufficient for that pur- 

 pose, these being mere adaptive modifications. In the true Bears 

 the number of true molars is on each side tioo above and ikree 

 below. In the Weasels it is only one above and two below. In 

 the Subursine group, to which I must add Bassaris, it is two above 

 aud two below ; and among these it is only Ailurus which possesses 

 the alisphenoid canal." 



He further expressed his views in a synopsis as follows : — 



" Fam. Ursid^. 



"Auditory bulla rising suddenly on its inner side, and more or less 

 flattened off towards the meatus. 



"Paroccipital process prominent, and neither flattened on the sur- 

 face of the auditory bulla, nor laterally compressed. 



" Foramen condyloideum exposed. A considerable foramen gle- 

 noideum. 



'^No caecum. No Cowper's glands. 



" Prostate gland not salient, being contained in the thickened walls 

 of the urethra. 



" Subfamily Ursina (of general geographical distribution). 



"A distinct alisphenoid canal. 



" Internal carotid artery reappearing externally, after passing 

 through its canal, and doubling back to enter the cranium. 



" True molars on each side 3. 



"Ursus (including the subgenera). 



" Subfamily Ailukina (confined to India). 

 "A distinct alisphenoid canal. 

 " True molars on each side g. 

 "Ailurus. 



23* 



