26 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



north side of Atico Point. ' The largest specimen reported to date 

 was only about 55 cm. (22 inches) long. 

 Range. — Southern Peru and Chile. 



Family RHINCODONTIDAE: Whale Sharks 



Body massive; tail with lateral keel; head and snout broad; eye 

 small, lateral, without nictitating membrane; spiracle small; mouth 

 very large, largely transverse; teeth small, numerous, subconic, 

 curved; nasoral grooves present; no nasal cirri; gill slits wide, at 

 least two above pectoral; two spineless dorsal fins, the first over ven- 

 trals; lower lobe of caudal large; anal small, opposite second dorsal; 

 pectoral large. 



Large sharks, pelagic in tropical seas. 



Genus RHINCODON Smith, 1829 



The characters of the single genus known are sufficiently indicated 

 in the family description. 



RmNCODON TYPUS Smith 



Rhincodon typus Smith, 1829, p. 443, Table Bay, South Africa (original descrip- 

 tion). — Fowler, 1941a, p. 220 (references). 



Rhinodon typicus Gunther, 1884, p. 365, Callao, Peru (record based on a section 

 of a dental plate). 



Rhineodon typus Gudger, 1935, p. 877 (reference to Giinther's record; also to an 

 account by William Nation in the South Pacific Times, January 24, 1878, 

 published at Callao). — Beebe and Tee-Van, 1941, p. 97, fig. 3 (range; 

 field characters; size; habits; references). 



This large shark is readily recognized by the color. The head is 

 spotted, and the body is covered with longitudinal and transverse 

 pale bands, forming a checkerboard, with a pale yellowish spot in 

 each quadrangle. 



The references to its occurrence in Peru apparently are all based 

 on a specimen from Callao. A length of at least 14 meters is attained. 



Range. — Warmer parts of the Atlantic, Pacific, and Indian Oceans. 

 Known from the Pacific coast of America from the Gulf of California 

 to Peru. 



Family SPHYRNIDAE: Hammerhead Sharks 



Head greatly depressed and expanded, more or less hammer-shaped; 

 eyes far apart, situated on the lateral margins of the expanded head; 

 nostrils far apart, situated in or near the anterior margin of the head; 

 spiracles absent; nictitating membrane present; the first dorsal large, 

 situated in front of ventrals; second dorsal and anal small, placed 

 opposite each other. 



A single genus is usually recognized. 



