576 DELriTlNTD.Ts. 



Genus ORCA, AVagkn- (1830). 



Size very large. No beak ; head conical and depressed. Dorsal 

 fin erect, A'ery higli, especially in the male. Pectoral fins large, 

 broadly ovate. 



Teeth few, 10 to 13 on each side above and below, very large, 

 often an inch or more in diameter, oval iu section, the longer 

 diameter across the jaw. Eostnun broad. Pterygoids separate. 

 Vertebra;: C. 7, D. 11-12, L. 9-10, C. 24 = 51 or 52. 



Tlie animals of this genus are highly predatory, living on seals, 

 whales, and other cetaceans, besides fish. They associate iu small 

 herds, and are said to attack and kill even the largest whales. 

 Many species have been described, but it is quite uncertain how far 

 they can be distinguished. 



382. Orca, sp. (O. gladiator ? — The Grampus or Killer). 



? Uelphinus orca, L. Si/st. Nat. i, p. 108 (1766). 



? Delpliiiuis gladiator, L'onnaferrc, Cef. p. 22 (1789). 



? Orca gladiator, Gray, Zool. Erch. 8f Terror, p. 33 ; Floioer, P. Z. S. 



188.3, p. 507 ; Trit'r, BeJphimdm, p. 187, pi. xlv, figs. 1, 2. 

 Cetacean, Holdsivorth, P. Z. S. 1872, p. 583 (figs. p. 584). 



A cetacean was seen by Mr. E. AV. II. Holdsworth in April 

 1868 off the west coast of Ct\ylon, and briefly described by him, 

 the description being illustrated by sketches. Th(^ animal ajipean^d 

 to be about 25 feet long, and ^^■as furnislied with a remarkable 

 straight, erect, narrow dorsal fin about 5 feet high. As figured 

 the fin appears scarcely a foot broad, with the anterior and posterior 

 margins nearly parallel. 



Fig. 188.— Gnirapus or Killer, Orca gladiafor. (Flower, art. "Mammalia," 

 ' Eucyclopasdia Britannica.') 



The only cetacean with a fin of this kind is Orca, but generally 

 the dorsal fin, though very high, es])ecially in the male, is re- 

 presented as triangular. Thei-e is a skull of 0. gladiator from the 

 iSeychelle Islands in the British Museum, so this species is an 

 inl"ial)itant of the Indian Ocean. 0. f/ladiator grows to about 20 

 feet in length, the teeth are 10-13 in number on each side above 

 and below, and the coloration is peculiar — the upper parts geiim-ally, 

 with the iins, black ; the lower to the vent white. l)ut the white 



