300 DELPHINID^. 



between Beluga and Orca. Grampus and Beluga^ are peculiar for 

 having teeth only in the front part of the lower jaw, as in Globio- 

 cephalus; but the teeth of Qrampus are permanent, while those of 

 Beluga are early deciduous. 



The lower jaw from the Cape Seas only differs from the lower jaw 

 of the typical specimen of O. Riehardsonii in being rather more 

 slender in front, just behind the gonyx and the end of the teeth- 

 line, and in the teeth being apparently rather shorter and more 

 slender ; but the bases of the teeth of the Epical specimen are entirely 

 exposed, and in the one from the South-African Museum they are 

 still imbedded in the dried gums; so that the difference is more 

 apparent than real. 



The upper edge of the orbit is raised into a decided marginal 

 ridge. The maxillary bones in front of the notch are rather ex- 

 panded and well bent up on the edge. 



The triangular space in front of the blowers is convex, evenly 

 rounded, and with a well-marked oblique groove on each side in 

 front. 



The intermaxillary bones are very broad, with a hard, shining, 

 smooth^ rather convex upper surface ; they cover fully two-thirds of 

 the upper part of the hinder portion, and much more, or at feast 

 four-fifths, of the front part of the beak. The palate is flat in front 

 and rather convex behind. The upper jaw is rather bent down at 

 the tip, and is destitute of teeth ; but has a submarginal line with 

 a few small pits. The lower jaw has four conical teeth on each side 

 in front, placed over the gonyx. 



Length of the skuU 18, of beak from the notch lOJ, of lower jaw 

 14^ inches ; width of the brain-case at the centre of the orbit 11, of 

 beak at the notch 7| inches. 



The triangle in front of the blowers in the skulls of the European 

 species is much elongated, the slender front part being produced 

 between the intermaxillaries nearly to the end of the beak. 



(1) Q. griseus, of Brest^ has only 2 . 2 teeth in the front of the 

 lower jaw (Gervais, I. c. t. 57. f. 5). 



(2) O. Bissoi, of Nice, has 5 . 5 teeth in the front of the lower jaw 

 (Gervais, Zool. et Paleont. Prang, t. 57. f. 1, 2). 



In the Cape species the triangle is shorter and much broader com- 

 pared with its length, the front side-margins being more transverse. 



(3) O. Riehardsonii. 



In O.Rissoi the outer edges of the intermaxillaries are sinuous and 

 rather contracted to nearly the middle of their length. In O. Rieh- 

 ardsonii the outer edges are rather slightly arched and bent out ; the 

 bones are widest in the middle of their length ; the nostrils are bent 

 to the left side, the right side of the skull being most developed. 



4. Grampus aflBnis. 



The teeth are 12. 12, small, conical, curved, very acute. Nose 

 rather concave on the sides. Intermaxillaries nearly as wide as the 

 jaws. Lower jaw obliquely truncated in .front. Length, entire, 24 



