176 BULLETIN 36, UNITED STATES NATIONAL MUSEUM. 



media.) Total leiifftli, 36.2^"'; leogtli of rostrum, 17.3*^^"'; breacULi of ros- 

 trum at base, 12<="'; breadth of rostrum at middle, 8.9""; breadth of in- 

 termaxillie. at same poiut, G.l"" ; breadth between orbits, 21.1""; length 

 of temporal fossa, 9.2*="'; depth of temporal fossa, 7.3"". 



(British Museum, lG72a. Type of F. attenuata.) Total length, 35""; 

 length of rostrum, 16.8""; breadth of rostrum at base, 10.7""; breadth 

 of rostrum at middle, 7.5'="'; breadth of iulermaxilla.^ at same point, 

 5.2""; breadth between orbits, 20.1"": length of temporal fossa, 8.4""; 

 dei)th of temporal fossa, 7.1*='". 



Habitat. — South seas. 



10. CEPHALORHYNCHUS Gray. 



Skull small. Rostrum moderate, broad. Rostral portion of inter- 

 maxillai tiat ; proximal end beveled off at the sides of the superior nares. 

 Symphysis of mandible short. Frontal plates of maxilhc nearly in one 

 and the same plane. Pterygoid bones separate. Teeth small, acute, 

 25 to 31. Vertebrae, 63 to 65. 



Size small. Head conical. Beak not marked off from the forehead. 

 Dorsal fin triangular or ovate. Pectoral fins elliptical (falcate in al- 

 hifrons). Black above, white below ; the white of the belly forms a 

 trident-shaped area posteriori}^, the lateral tines of which extend up- 

 ward obliquely on the sides. 



CEPHALOEHYNCHUS IIEAVISIDEI Gray. 

 (Plate 31, figs. 1 and 2.) 



General form like that of Phocwna. Mouth small. Pectoral fins el- 

 liptical. Dorsal fin triangular. Back, head, tail, and fins black. A 

 large, sharply- defined area of white or pale yellow on the ventral sur- 

 face of the body, extending from the breast to the vent; expanding 

 posteriorly to form a trident, the lateral tines of which extend backward 

 obliquely on the sides; expanding also anteriorly on the breast and up- 

 ward behind the base of the pectoral fins. 



Teeth P to ^^ Vertebn^: C. 7; D. 13; L. 15; Ca. 30 = 65. Skull 



Jo 30 7 7 7 



small. Rostrum rather less than one-half as long as the entire skull; 

 broad and with an obtuse termination. Intermaxilla' onl}" slightly ex- 

 panded proximally, flat distally. Pterygoid bones short and widely 

 separated. Vomer extending nearly to the extremity of the rostrum. 

 Temporal fossiie moderate, rounded, longer than deep. 



Measurements of the exterior. — (British Museum. Type-skin, mount- 

 ed.) Total length, 109.2*='"; extremity of snout to corner of mouth, 

 15.5""; to base of pectoral fin, 26.7"" ; to base of dorsal fin, 51.6"" ; ver- 

 tical height of dorsal fin, 8.2""; length of pectoral fin, 14.5""; breadth 

 of flukes, 24.7"". 



Measurements of the sliull.—iJAxx^. (}CW\^i. nat., Paris, ^3061). Total 



