2 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 9 



Numerous large specimens of this species were examined at a shark 

 fishery on Cerros Island, where they were secured for their oil and fins. 

 They are known locally as the "Soup-fin Shark." 



Sphyrnidae Hammer-headed Sharks 



Sphyrna zygaena (Linnaeus) 



Perhaps the most abundant species of shark in the Galapagos Islands. 

 Specimens were taken measuring up to 12 feet in length. 



Rhinobatidae Guitarfishes 



Rhinobatos leucorhynchus (Giinther) 



One from Tenacatita, Mexico, December 10, 1931. Length 140 mm. 

 A row of distinct spines down the back, a pair of spines on each shoulder, 

 and spines on the orbital ridge. Color in alcohol grayish without distinct 

 markings. 



Torpedinidae Torpedoes 



Discopyge ommata Jordan and Gilbert 



One from Port Culebra, Costa Rica, February 25, 1932. Length 165 

 mm. Back mottled with ocellated spots and with a black ring in the 

 center of the disk. 



One from Port Culebra, Costa Rica, February 25, 1934. Length 65 

 mm. This specimen is mottled and marbled with brown over the back 

 with a distinct round white spot surrounded by rings of black and white 

 on the center of the back. 



Elopidae Tenpounders 



Elops affinis Regan 



One from Tenacatita, Mexico, December 10, 1931. Length 305 mm. 

 Silvery with the dorsal, anal, and caudal washed with yellowish color. 



Albulidae Ladyfishes 



Albula vulpes (Linnaeus) 



One from Acapulco, Mexico, December 15, 1931. Length 64 mm. 

 Grayish, with about 12 dark bands over the back. 



