CETACEA. 103 
8. LAGENORHYNCHUS THICOLEA. 
_ Skull rather narrow behind. Beak elongate, about 4 longer 
than the length of the head, rather dilated and concave above 
_ behind, with the side edges in front of the notch elongate, keeled 
and turned up; the middle of the beak flat, with flat shelving 
sides, the shelving part being broader and forming a slight keel 
in front. Intermaxillaries flat, gradually tapermg. Triangle to 
- near middle of the beak, concave on the sides and keeled m the 
middle behind. Teeth 48? very slender, curved, elongate, conical, 
' tapering, acute; the front one very small. 
_ Lagenorhynchus Thicolea, Gray, Proc. Zool. Soc. 1849; Zool. 
Erebus & Terror, t. 36, med. Skull. 
_ Inhab. West coast N. America. 
a. Skull. Imperfect behind. From Dr. Dickie’s Collection. 
ia in. lin. 
Length of skull, entire.......... 14 62 (end of nose injured. ) 
» ‘i eM IE acd dig SECs 8 4 
is teeth-line, jo. 5 /ad5 0% fee | 
>. " LOW OE JAW 4:6 )6:0 05,0000 56 12 3 (entire.) 
Be width at orbits.............e6. ree 
ie ae oe ee 3 11 
pu eanidie of beak . ...:... Bi 
»  intermaxillary at middle 1 2 
i of condyles.:..u:) i 6. +. 3 0 
12. DELPHINAPTERUS. 
Head rather convex, shelving towards the nose. Nose rather 
eta obscurely divided from the forehead. Dorsal fin none. 
_ Back rounded. Pectoral oblong, rather slender. Skull mode- 
_ rate; beak broad, depressed, tapering, rounded above; the tri- 
_ angle before the blower, elongate, extending nearly to the middle 
of the beak. Palate flat. Teeth conical, tapering, acute, curved. 
_Symphysis of the lower jaw short. 
_ Delphinapterus, Gray, Zool. Ereb. § Terror, 35. 
_ Tursio, pars, Wagler, N. S. Amph. 34. 
~ Delphinus, sp. Lacep. 
_ Delphinapterus, sp. Blainville, not Lacep.; Lesson, Voy. 
Ll. DELPHINAPTERUS PERONII. PERON’s DOLPHIN. 
Black; beak, pectoral fins, and under part of body white. 
mm Teeth 33-48. 
 Delphinus Peroni, Lacep. Cet.517; F. Cuv. Cetac. 164; D’ Ord. 
Voy. Amér. Mérid. Mamm. t. 21. f. 5. 
