True On /South American DelpliimdcB. 1B5 



*Phocaena (Hyperoodon?) albiventris Perez in lit." (1893, p. 8, 



pi. 2, fig. 3). 



"Tursio (Phocsena) aHbiventrts Perez 1 ' (1S9C, p. 15, pi. 4, fig, 3: pi. 5, 

 fig. 3; pi. 6, fig. 3?). 



Why the generic name Hyperoodon should have been used in 

 connection with this species is far from clear, as nothing about 

 it suggests that genus in any way. The use of the generic name 

 Tursio is much more easily justified, for Gray, in 1866, in-eluded 

 under it one species, Tursio eutropia, which is probably closely 

 related to, or identical with, Dr. Perez Canto's albiventris. The 

 original type of Gray's Tursio in 1844, however, was the species 

 now generally known as Tursiops tursio, which is certainly not 

 congeneric with eutropia. The point is of no special import 

 ance as the generic name Tursio was used by Fleming and by 

 Wagler prior to the date at which Gray first employed it.* 



The proper name for Delphinus eutropia Gray is Cephalo- 

 rhynchus eutropia. Whether P. albiventris of Perez Canto is 

 really identical with that species is not entirely certain, though 

 there is a strong probability that such is the case. I was at 

 first inclined to associate albiventris with LagvnorhyncJius ob- 

 scurus (Gray) which it certainly resembles in proportions, 

 though not exactly in color. Dr. PhilippPs figures of the skull, 

 however, show that his species is a Cephalorliynvhus, and his 

 measurements agree well with those of the type-skull and other 

 specimens of C. eutropia, except that the beak appears to be a 

 little longer. Dr. Perez Canto's description and figure of the 

 exterior show that the color-pattern resembles that of other spe 

 cies of Cephalorhynchus except that the posterior lateral white 

 mark is not divided by an anteriorly-directed arm of black, to 

 form a trident. ^ The shape of the pectoral fins is that of a 

 CephalorhyncJms. As the exterior of C. eutropia has remained 

 unknown hitherto, this identification, if correct, is of much in 

 terest. The type and another specimen of C. eutropia in the 

 British Museum are from the coast of Chili, and the skull in the 

 United States National Museum is also believed to be from that 

 locality. 



Trouessart cites albiventris under the genus Cephalorhynchus, 



*See Palmer, T. S. Notes on three genera, of Dolphins. <Proc. 

 Biol. Soc. Washington, XIII, 1899, p. 23, 



