True On South American Delphinidce. 137 



they represent.* Dr. Philippics figures go to the other extreme, 

 and show the caudal region as an elongated cone. It is not 

 likely that a photograph would substantiate either of these 

 forms, so that this character is hardly worth insisting upon. 

 The dimensions of the body appear to be quite alike in the two 

 species. The excellent figures of the skull P. philippii show 

 that it is very closely allied to spinipinnis. The differences in 

 detail which Dr. Philippi points out seem to me individual 

 rather than specific. It is to be remembered that P. spinipinnis 

 is a South American species, though from the Atlantic instead 

 of the Pacific. 



On the whole, I am inclined to the opinion that spinipinnis 

 and philippii are specifically identical. 



Trouessart cites philippii under the genus Cephalorhynchus, 

 with a mark of interrogation,-)- but I am unable to find any war 

 rant for that association. 



After Dr. Perez Canto had sent the description of this species 

 to Dr. Philippi, he decided to publish an account of it himself, 

 which he did in the Actes de la Societe Scientifique du Chili, 

 5, p. 227, 1896, under the name of Phoccena philippii. 



"Phocama posidonia Philippi" (1893, p. 9, pi. 2, fig. 1). 



The skull of this species is not figured or described, but judg 

 ing from the shape of the head, it should be assigned to the 

 genus Lagenorhynchus. There is nothing about it which sug 

 gests a Phoccena. Dr. Philippi compared it with L. fitzroyi, 

 which he very properly considers as closely allied to it, having 



*Beddard (Book of Whales, 1900, p. 251) regards the caudal ridges 

 shown in Burmeister's figure of P. spinipinnis as "the most remarkable 

 character," and views it as a survival of an embryological character. I 

 cannot subscribe to this opinion for the reason given above. It is true 

 that Ball's figure of Phoccena dallii, which I copied in Bull. 36, U. 8. 

 Nat. Mus., pi. 37, fig. 1, shows similar ridges, but I believe this to be an 

 inaccuracy also. It appears to be a matter of special difficulty to make 

 a correct graphic representation of the caudal region of a cetacean. 

 Some artists exaggerate the thinness of the superior and inferior mar 

 gins, while others give this region the shape of a truncate cone, and do 

 away with the ridges altogether. 



f Trouessart, Cat. Mam., 1898-99, p. 1041. 



