12. PHOCExXA P. DALLII. 1.5. ORCELLA 181 



PHOC.'ENA DALLII True. 



(Plate 37, figs. 1 ami 2.) 



Head sloping-. Lower jaw protruding- slightly beyond the upper. 

 Mouth short. Dorsal fin beginning a little behind the juncture of the 

 first aud secoud thirds of the total length ; moderately high and falcate, 

 its front edge furnished with faintly- marked tubercles. Pectorals as in 

 P. communis. Dorsal and v^entral margins of the botly, between the 

 vent aud the origin of the flukes, raised into prominent thin ridges. 



General color black. A cordate area of white occupies the belly anil 

 lower half of the sides, from a point in a line with the anterior margin of 

 the dorsal fin to one considerably behind the vent. This area is faintly 

 streaked with very fine dark lines, especially numerous near the median 

 line, but only visible on close inspection. The doi-sal fin is tipped witli 

 white. Eye blackish. 



Teeth ^, very small. Vertebral: C. 7; D. 14 (or 15); L, 27; C.i. 

 49=97 (or 98). 



Skull as in P. communis, but the beak relatively shorter and Hit, ami 

 the temporal fosScC smaller. The maxillaries also shorter proximally, 

 and the mandible less deep between the corouoid process and angle. 

 ]S"ares very large. All the cervicals united, as are also the last four 

 caudals. First thirty caudals with chevron bones. Formula of pha- 

 langes as follows: 1, 1; II, G; 111, 4; IV, 2. The two distal pha- 

 langes of fingers 2 aud 3 and the outermost of finger 4 very imper- 

 fectly ossified. 



Measurements of the exterior. — $ adult (type). Total length, 72 inches 

 (182.9""); length of mouth, 3.5 inches (8.8'^''») ; length from tip of snout 

 to beginning of dorsal, 27.5 inches (G9.8''"); length of pectoral (anterior 

 margin), 8 inches (20.3'"') ; vertical height of dorsal, G inches (15.2'"'); 

 breadth of flukes, 18.5 inches (47'"'). 



Measurements of the skull. — 5 adult (type). Total length, 33.3'"'"; 

 length of beak, 14'"'; breadth of* beak at base, 9.5''"; at middle, 5.7''"'; 

 breadth between orbits, 1G.5'"'; length of tooth-line, L2.7'"'; depth of 

 temporal fossa, 2.6"". 



13. ORCELLA Gray. 



Rostrum short and broad; rostral portion of intermaxilhe broad. 



Pterygoids widely separated from each other. Symphysis of mandi- 

 ble short. Teeth 12 to 14; small, conical, and acute, occupying nearly 

 the whole length of the rostrum. Vertebrji?, G2 to 63. 



Held globose; beak wanting. Djrs:il flu small, falcate. Pectoral 

 fins small, broad at the base, and obtusely pointed. Color slate-gray 

 above, lighter below, with or without irregular streaks. 



