238 PROCEEDINGS OF THE ACADEMY OF [1889. 



ever shown in the dentition of Dinietis, namely, the fact that the 

 crowns of the lower incisors form a continuous row and the second 

 one is not forced out of line. The vertebrae of the genus before us 

 are also rather feline, but with certain resemblances to the civets and 

 especially to Oryptoprocta. The hind-limb has very little about it 

 that reminds one of the cats, the most important resemblance being 

 the degree of retractility shown by the claws, though this is shared 

 by some civets. On the other hand both in its proportions and in its 

 individual members the hind-limb and foot of Dinietis approximates 

 closely the corresponding parts of many of the Viverridce, though 

 with certain features which are more primitive than occur in any 

 living member of that family, for example, the well developed third 

 trochanter of the femur, the very flat ankle joint and the articula- 

 tion of the cuboid with the astragalus. And it further seems clear 

 that thp numerous viverrine characters are not the result of independ- 

 ent development, or " convergence." 



In a former publication (No. 16, p. 153), I referred Dinietis to 

 the Cryptoproctidce ; but since that account was written, I have 

 had an opportunity to study specimens of the Madagascar genus, 

 which have led me to agree with Mivart in referring this genus to 

 the Viverridve, to which Dinietis manifestly does not belong. The 

 Nimravidie, alone remain, and the characters of the base of the 

 skull are so exactly like those of Dinietis, that in spite of differ- 

 ences in the feet, I feel constrained to follow Cope's example and 

 place the White River genus in that family, of which it, probably, 

 together with Archcelurus, will form the more primitive section. 



Comparing the Nimravidce with the Felidce and Vioerridce, we 

 reach the following results : — 



1. The muzzle is short as compared with the cranium. 



2. The auditory bulla is inflated, but (in the genera in which this 



region is known) shows no external sign of division. 



3. The bulla is more prominent towards its inner than towards its 



hinder border. 



4. There is, probably, an almost complete bony septum between the 



chambers. 



5. The bony meatus is not produced nor imperfectly ossified below. 



6. There is a distinct carotid foramen. 



7. There is an alisphenoid canal. 



8. The palatine foramina are situated about midway in the palate. 



