278 A BOOK OF WHALES 



suggestive of that of the Porpoises, and the form of 

 the pterygoids is much like what is found in the 

 genus Plwccena, as also the elevations upon the 

 pre-maxillae. They have not a beak well marked 

 off from the rest of the head ; but this fact of struc- 

 ture has not been incorporated into the generic 

 diagnoses, since in C. hectori there is a hint of one, 

 which is indistinctly marked off from the forehead. 

 The small size and non-falcate form of the pectoral 

 limb might perhaps be added as a generic character ; 

 but in C. albifrons these limbs are, though small and 

 elongated as in the other species, slightly falcate. 



Cepkalorhynchus heavidsidii, Gray * (Plate XVIII.), 

 the first described species of the genus, has the 

 pectoral fin elliptical and the dorsal fin triangular. 

 Teeth, 25-30. Vertebral formula: C. 7; D. 13; 

 L. 15; Ca. 30 = 65. Pterygoids short and widely 

 separated. Length, about 48 inches. 



The colour of this dolphin appears to be black 

 with a good deal of white or pale yellow on the 

 ventral surface. But there is evidently some variation, 

 as F. Cuvier's " Marsouin du Cap "t is stated to be 

 entirely black save for a white spot on each side. Sir 

 W. Flower and Mr. True unite these two forms, and 

 the former suggests that Cuvier's "species" may be 

 a melanic variety of the more typical form. The first 



* Spicil. Zool., 1828, p. 2. 



t This has been called Delphinus capensis. Other species, called by 

 Frederick Cuvier D. cephalorhynclms and D. hastatus, are believed to be 

 synonymous. 



