1883.] PROF. FLOWER ON THE DELPHINID^E. 495 



with Quoy and Gaimard's D. cruciger can be made. Lastly, L. 

 breviceps (fig. 2) is evidently the same as Gray's Delphinus obscurus 

 or Clymenia obscura (Zool. ' Erebus ' and ' Terror,' pi. xvi.). 



Clymenia. '■ 



Olymene, Gray, P.Z.S. 1864, p. 237. 



Clymenia, Gray, Synopsis of Whales and Dolphins, p. 6 (1868). 



Prodelphinus, Gervais, Ostcographie des Cetaces, p. 604 (1880). 



This is not a very homogeneous group, and may perhaps require 

 further division when the characters of some of the animals' at 

 present referred to it are better known. The cranium has no lateral 

 grooves on the palate, by which it is distinguished from Delphinus 

 proper, to which otherwise some of the species present a close re- 

 semblance. The pterygoid bones are well developed and touch for 

 the whole length of their inner sides, as in Delphinus and Tursio. 

 The rostrum is long and narrow, or of moderate width, always more 

 than half the entire length of the skull. The symphysis of the 

 lower jaw is less than one fifth of the length of the ramus, but varies 

 according to the width of the rostrum. When the rostrum is wide 

 the symphysis is short ; when narrow the two rami of the mandible 

 come in contact for a larger space. The teeth are small, the largest 

 less than 3 millim. in diameter at the base, and numerous, exceeding 

 30 on each side of each jaw. The vertebrae in all the known 

 skeletons (which are very few) from 73 to 76 in number. 



This group contains a considerable number of forms, almost all 

 known by the skulls alone, which vary chiefly in the comparative 

 width of the rostrum, passing oflF almost insensibly into Lagenorhyn- 

 chus on the one side, and Steno on the other. In fact, two species 

 which I place in this group, on account of their close resemblance 

 to others undoubtedly members of it. Gray includes respectively 

 in the two genera just named. 



The skulls at present referred to this genus can be separated into 

 at least four distinct types, distinguished chiefly by the comparative 

 breadth of the rostrum. 



A. The broadest form is represented by skulls which in the 

 British Museum are called Clymenia obscura, being referred to the 

 stuffed specimen described as Delphinus {Grampus) obscurus in 

 Gray's ' Spicilegia,' p. 2 (1828), which Schlegel identifies with D. 

 superciliosus of Garnot and Lesson (' Voyage de la Coquille,' 1826), 

 of which, however, so little is really known that the identification 

 cannot be verified. 



The type specimen, from the Cape of Good Hope, described and 

 figured in the ' Spicilegia,' is now in the British Museum, and pre- 

 sents much resemblance in its external characters to one of the Tur- 

 siops group, liaving a high falcate dorsal fin and long falcate pectorals. 

 There seems no reason why the skulls which Gray subsequently re- 

 ferred to this species may not belong to it, as the teeth and palate, 

 as fur as they can be seen, appear to correspond ; but unless the 

 wliole cranium could be removed from the skin so as to allow of a 



33* 



