108 BULLETIN 36, UNITED STATES NATIONAL MUSEUM. 



10. CEPHALORHYNCHUS Gray. 



Cephalorliynchns, Gruy, Cat. Cctacea, Brit. Mas., 18.')0. p. 100. 

 ?CeplialorLyiiqueR, F. Cuvier, Hist. Nat. des ( etacces, 1836, p. 1.5G. 

 Entropid, Gray, P. Z. S., LoniloD, 186:2, p. 145. 

 Eiitropia, Gray, Synopsis of Whales aud Dolphins, 1868, p. 7. 



Although Gray credits the name Ccphalorhynchus to F. Cuvier, it 

 was the former naturalist who first made a formal separation of the 

 species. Cuvier states, at the place cited: 



Nous les aiirions s^pardes des daiiphius proprement dits sons le iiom de cdphalorliyn- 

 qiies, si 'ces diftereuces exterieures [[ircvionsly pointed out] cuaHent eutraind des dif- 

 ferences iutdrieures plus in;irqii6es. Uu cxanien do ces especes pins ai)profon(li <|ue 

 celni que nous en avons pu faire determinera peut-etre plus tard cette separation.* 



This aoristical grenus includes representatives of four genera, the first 

 mentioned being D. rostraius, a species now referred to the genus Stow 

 If Ceiihalorliynchus were to be accepted upon the authority of Cuvier, it 

 would have to be applied, under the rules, to the species included in Sicno. 



Gray's distinctions are quite vague, aud he has included I), ohscnnis 

 in his subgenus, which is now referred to Lagenorhynchns. His first- 

 mentioned species, however, is J). ITeavisidei. Furthermore, his defini- 

 tion of Cephalorhynclms Is, as already stated, a formal one, and the 

 name itself is Latinized. 



Professor Flower has left but little to be said regarding this genus 

 and the species included under it. More facts must be forthcoming be- 

 fore the species can be placed upon a satisfactory basis. 



The principal cranial characters of the genus seem to me to lie in (1) 

 the se]iaration of the pterygoids, (2) the great height of the nasal re- 

 gion, and (3) the expansion of the beak at the middle of its length. 

 The expansion of the beak causes the rami of the mandible to bow out. 

 As they are also bent downward toward the symplysis, the shape of 

 the jaw is quite peculiar and characteristic. 



CEPHALORHYNCHUS HEAVISIDEI Gray. 



Dclph'nnis (Oravipiis) Ilcavisuki, Gray, Spic.Zool., 1828, p. 2, pi. ii, fig. 6. 

 DrJphiniis (Cc2)halorl> ynchus) Heavhidei, Gray, Cat. Cctacea Brit. Mus., 18r)0, p. 107. 

 DcJplihuis capoisis, F. Cuvier, Hist. Nat. des Maiumireres, liv. .58, 1829. 

 Ddphinus cephalorhijnchus, F. Cuvier, Hist. Nat. der Cetac6cs, 1836, p. 158. 

 D. liastatHs, F. Cuvier, Hist. Nat. dea Cetacees, 1836, p. 161. 



Orca capensis, Van Beueden {nee Gray), Bull. Acad. K. Belj;., 2d ser., xxxvi, 1873, 

 p. 32, 1 fig. 



Professor Flower has summed up the facts relative to this species in 

 such a manner as to leave little for me to add. T append measurements 



* This is a good example of what may bo called gratuitous nouieuclature. The au- 

 tlior does not erect a name upon differences which he has discovered, hut suggests 

 that in case valid distinctions art- found in the future such and such an appellation 

 would be appropriate. Similar exauiples are frequent in zoological literature. 



