34 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 72 



ment Orca has gone further than any other genus of the family. It 

 has habituated itself to living on large prey such as seals and the 

 smaller cetaceans, and it even slashes into the largest. The teeth are, 

 it is true, relatively few, about 12 in each jaw, but in compensation 

 they are massive. 



Orcella has reached higher than Orca in the great breadth of the 

 intermaxillary, but it must have originated at a level lower than that 

 on which Orca stands, sinte its teeth are small and rather more 

 numerous, while its hand is essentially like an ordinary porpoise hand. 

 The genus gives the impression of being a dwarf form with notice- 

 ably large braincase in proportion to the face. 



The following genera of Globicipites must have originated from 

 Delphinids that were essentially like Orcella but without the dwarf- 

 ing. Each has gone its own way. There is, however, one peculiarity 

 that unites them: the hand has acquired an uncommon length and 

 narrowness, though in different degrees, at last with an unusual 

 number of phalanges in the second finger. 



In ''" Grampus " the intermaxillary has retained a breadth similar 

 to that in Orcella. Although the hand is long and narrow there are 

 only about eight phalanges in the second finger. The chief peculiarity 

 of the genus lies in the atrophy of the dentition : only a few and 

 rather small teeth remain. These are at the front of the mandible, 

 and with age they may entirely disappear. 



In Psendorca the hand is essentially as in Grampus. But the inter- 

 maxillary has acquired a very noticeable breadth anteriorly, and the 

 dentition is developed in a similar manner as in Orca. 



The intermaxillary is conspicuously wide in Globiceps [Globi- 

 cephala'] also ; it may be even wider than in Pseudorca. Peculiarities 

 of Globiceps are : that the nostril is pushed unusually far backward, 

 that the dentition is atrophied so that only a few, about 10, small 

 teeth remain, situated at the front of the jaws, and that the hand is 

 conspicuously long, with as many as 14 or more phalanges in the 

 second finger. 



The- section Phocance presumably originated among the most primi- 

 tive Globicipites or perhaps Lagenorhynchi. That which places this 

 group in contrast not only with the Lagenorhynchi but also with all 

 other Delphinids is the peculiar form of the teeth. The teeth are 

 present in large number and are of small size. Some of the foremost 

 and hindmost may have about the usual conical crown, and all of them 

 are single rooted. Most of the teeth, however, have the crown com- 

 pressed, widened out fan-wise or leaf-wise, and often with notches in 



