496 PROF. FLOWER ON THE DELPHINID^. [NoV. 20, 



complete comparison, absolute certainty on this point cannot be 

 attained. But as the species seems to be a common one both at the 

 Cape of Good Hope and New Zealand, the question will probably 

 soon be settled by the examination of recent specimens. 



A skull is also figured in Gervais's ' Osteographie ' under the name 

 of Lagenorhynchus breviceps (pi. xxxvi. fig. 2). There is a skeleton 

 at Leiden from the Cape, described by Schlegel in his ' Abhaudlun- 

 geu ' (p. 22). The figure of the upper surface of the skull (tab. 1. 

 fig. 3) is not quite correct, the rostrum not being sufficiently rounded 

 at the sides. The vertebrce are C. 7,D.13(15?), L, 20 (18 ?), C. 33, 

 total 73. The teeth about 3°. In the British Museum are four 

 skulls, two from the Cape and two without locality. In the College 

 of Surgeons Museum two, both from New Zealand ; and there is 

 one skull in the Cambridge University Museum. Hector figures a 

 skull from New Zealand (Trans. N.-Z. Inst. vol. v. pi. i.). The teeth 

 in all these specimens are from 30 to 33 in number. Those in the 

 Cambridge specimen are slightly larger than in the others, being 

 almost 3 millim. in diameter. In all the " triangle in front of the 

 blowers," formed by the premaxillse, is flat and elevated on each 

 side above the maxillae, which slope down laterally to the supra- 

 orbital ridge. The most Ofjposite form to this among the Dolphins 

 is Sieno, where the " triangle " is concave, the middle part being 

 sunk between the lateral ridges, and though the latter are raised 

 above the supraorbital plates of the maxillae, these, instead of falling 

 away laterally, rise up, forming an elevated supraorbital ridge. Most 

 of the other Dolphins are intermediate in this respect. In the 

 rostrum the premaxillse are thick and well raised above the maxillae, 

 as in Tursiops tursio, to which the cranium bears considerable resem- 

 blance, though of much smaller size. 



Chjmenia similis, Gray, from the Cape of Good Hope, is pro- 

 bably of the same species ; the only difference being a constriction 

 of the posterior part of the palate in the region of the palatine bones, 

 as figured by Gray (P. Z. S. 1868, p. 147) ; but this is a character 

 which varies in different specimens of 0. obscura. 



A single skull in the British Museum (from the Pacific Ocean) de- 

 scribed and catalogued as Lagenorhijnchus thicoleu^, and subsequently 

 as Electra thicolea, and figured under the former name in the supple- 

 mentary plates to the ' Zoology of the Erebus and Terror' (pi. 36), 

 is very like that of Clymenia obscura ; but without knowledge of the 

 rest of the skeleton, it is impossible to say whether it really belongs 

 to this group or to the one to which Dr. Gray assigned it. It is of 

 the same size as C. obscura, but the rostrum is more depressed, the 

 premaxillae less prominent, and the nares and the premaxillae in front 

 of the nares are narrower. The lower jaw is somewhat stouter, the 

 ramus deeper from above downwards, and the symphysis more ver- 

 tical. The most valid distinction, however, seems to be in the teeth, 

 which are more numerous and rather more slender and close toge- 

 ther. Unfortunately they are very incomplete in this much mutilated 



1 P. Z. S. 1849, p. 2. 



