COPEIA 63 



of southern California. Only this week (June 1) 

 Mr. Samuel Hubbard of Oakland, brought me 14 

 fine specimens of this species from Saratoga Springs, 

 Death Valley, where Mr. Hubbard says they are 

 very abundant. 



Barton Warren Evermann, 



San Francisco, Calif. 



A COMPARISON OF ATLANTIC AND 



PACIFIC SPECIMENS OF THE 



HAMMER-HEAD SHARK, 



SPHYRNA ZYGAENA. 



In their review of the elasmobranchs of Japan, 

 Jordan and Fowler (Proc. U. S. Natl. Mus., XXVI, 

 593, 1903) raise the question whether the hammer- 

 head of the Pacific usually referred to Sphyrna zy- 

 gaena is really identical with that species from the 

 Atlantic. They say that specimens from the two re- 

 gions need comparison. 



I have recently made a detailed comparison of 

 hammer-heads from the Atlantic and Pacific and 

 found them absolutely similar, and this note is in- 

 tended to record this fact. 



The specimens examined were, one from Woods 

 Hole, Mass., 60.5 cm. in length, and two from Japan 

 respectively 51 and 56 cm. The three were found 

 entirely similar in all characters that could be con- 

 sidered specifically diagnostic — such as, body propor- 

 tions, shape and position of the fins, form and relative 

 size of the "hammer," and the size and position of 

 the eye, mouth and gill area. The coloration only 

 was a little different, the Woods Hole specimen 

 being dark brown above while the Japanese ones 

 were blackish gray. This, however, is not important 

 since differences in coloration are not rare in fishes 

 from widely separated localities, and besides, it may 

 have been due to different preserving fluids having 

 been used in the two cases. 



