36 



P^ISHES OF NORTH CAROLINA. 



10.. SPHYRNA ZYG^NA (Linnaeus). 

 " Hammer-head" ; "Hammer-headed Shark". 



Squalus zygcena Linnaeus, Systema Naturae, ed. x, 234, 175S; Europe, Ameiii-a. 



Sphyrna zygaena. Yarrow, 1877, 217; Beaufort. Jordan & Gilbert, 1879, 387; Beaufort. Jordan, 1887, 26; 

 Beaufort. Jordan & Evermann, 189G, 45. Wilson, 1900, 355; Beaufort. 



Diagnosis. — Body slender, head about twice as wide as long; nostril near eye, prolonged 

 into a groove; first dorsal large, second dorsal small, anal small but larger than second dorsal; 

 pectorals large. Color: gray above, white beneath, {zygcena. an ancient Greek name for this 

 fish.) 



Fig. 6 (a and b). Hammer-headed Shark. Sphyrna zygcena. Dorsal and 

 dorso-Iateral views. 



This singular species, at home in the warm seas, occurs as a straggler on our 

 Atlantic and Pacific coasts. Dr. Yarrow records a single specimen from Beau- 

 fort. Another was taken near Morehead in 1902. Professor Wilson states that 

 some years the young are very abundant at Beaufort in early summer. This is 

 a voracious species, attaining a length of over 15 feet; it often swims with its 

 dorsal and caudal fins exposed. 



Family CARCHARIID^. The Sand Sharks. 



Voracious, moderate-sized sharks, belonging to a single genus. Body 

 elongate; snout sharp; mouth crescentic; teeth long, narrow and sharp, mostly 

 with 1 or 2 cusps at base; gill-slits large, all anterior to pectorals; both dorsal fins 

 and anal fin of similar size, first dorsal posterior to pectorals; pectorals short; no 

 keel on peduncle; upper caudal lobe about twice length of lower, with a well- 

 marked notch below; nictitating membrane absent; spiracles reduced to mere 

 pores. 



