CETACEA. 69 



*** Dorsal fin posterior, oblong, truncated at the end? Jaws 

 curved up. Diodon, Lesson. 



4. HYPEROODON DESMARESTII. DESMAREST'S HYPEROO- 



DON. 



Delphinus Desmarestii, Risso, Europ. Merid. iii. 24. t. 2. f. 3 ; 



F. Cuv. Cetac. 159. 



Le Diodon de Desmarest, Lesson, (Euv. Buff. i. 124. t. 2. f. 2. 

 Orca (Desmarestii), Wagler, N. S. Amph. 34. 

 Inhab. Nice : common, March and September. 



" Steel-grey, with numerous, irregular, white streaks, beneath 

 white; body thicker in the middle; tail slender, long, keeled, 

 rounded on the belly ; head not swollen, ending in a long nose ; 

 upper jaw shorter, toothless, lower much longer, bent up, and 

 with two large conical teeth at the end ; teeth nicked near the 

 tip ; the eyes small, oval ; blowers large, semilunar ; pectoral fins 

 short, dorsal rather beyond the middle of the back, nearly above 

 the vent; the caudal fin broad, festooned. Length nearly 16 

 feet. It differs from D. Diodon of Hunter in the forehead not 

 being swollen, and in the lower jaw being produced and bent up, 

 the pectoral being pointed, the dorsal more obtuse, and the body 

 being white-streaked." 



This species is only known by the above account extracted 

 from Risso. F. Cuvier placed it in the restricted genus Delphi- 

 nus. Risso appears more correctly to have compared it with 

 Hyperoodon, but it differs from that genus in several particulars, 

 especially in the form of the forehead and of the dorsal fin. 



Lesson (Tab. R. A. 200) forms of this species, and the Phy- 

 seter bidens, Sowerby, the subgenus Diodon \ 



ft Crest of skull thick and close together on the upper edge. 



5. HYPEROODON LATIFRONS. 



Skull large, heavy, solid, the reflexed part of the maxillary 

 bones very thick and thickened internally, so as nearly to touch 

 each other in front of the blower, much higher than the hinder 

 part of the skull ; lower jaw rather curved up at the top ; teeth 2, 

 solid, conical, acute, rather compressed. 



Hyperoodon latifrons, Gray, Zool. E. $ T. 27. t. 4, skull. 

 Inhab. North Sea. Coast of Lancashire ; Orkneys ; Greenland. 



a. Skull imperfect. Orkneys. From Mr. Warwick's collection. 



Length of skull (wanting the end) . . 62 inches. 



Height of skull behind 42 



The skull figured in Voyage of the Erebus fy Terror, tab. 4. 



