30 NEW YORK STATE MUSEUM 



torals and ventrals; second dorsal very small, slightly behind, 

 and rather smaller than anal; anal fin much shorter than dis- 

 tance from anal to ventrals; pectorals rather large, reaching 

 about to middle of first dorsal; ventrals small. 



Color gray; caudal fin with a narrow blackish edge. Cape 

 Cod to Brazil, very common on the southern Atlantic coast. 



The green-backed shark, Sqiialus imnctatus, of Mitchill is said 

 to belong to this species. His example was 31 inches long, but 

 he was incorrectly informed that the shark reaches two or three 

 times that size. Mitchill wrote: 



" When this shark is in the water his back and sides appear 

 greenish. But soon after his exposure to air, and immediately 

 after his death, the hue becomes a pale ash, leaden, or dove, with 

 but trifling variegations. The parts about the mouth, neck, 

 and belly are of a clear white. The upper side of the pectoral 

 fins resembles the color of the back; the lower partakes of the 

 complexion of the belly. The openings of the excretory ducts 

 on the snout and lips are blackish. 



" The shark is very common on the coast of our southern 

 states; it reaches the length of 3 feet." 



Family sf-hyrnidae 



Hammerhea'ded Sharks 



Genus sphyrxa Rafinesque 



Head laterally extended, hammer-shaped or kidney-shaped, 

 the eyes on the ends of the " hammer " and the nostrils anterior; 

 mouth inferior, crescentic; teeth in the jaws similar, oblique, 

 notched on the outside near the base; no spiracles; last gill- 

 opening over the pectoral; first dorsal large, nearer pectorals 

 than ventrals; second dorsal and anal small; pectorals large; a 

 pit at the root of the caudal; caudal fin notched near its tip, its 

 lower lobe developed. 



13 Sphyrna tiburo (Linnaeus) 



Shovclhead Shark; Bomiethead 



Sqtiolus tihuro Lixnaeus, Syst. Nat. ed. X, 234, 1758. 



Zygaena tiburo Gunther. Cat. Fish. Brit. Mus. YIII, 382, 1870. 



Reniceps tihuro Gill, Anu. N. Y. Lye. Nat. Hist. YIII, 412, 1861; Jordan 



& Gilbert, Bull. 16, U. S. Nat. Mus. 25, 1883. 

 ■Sphifrna tihuro Jordan & Evermanx, Bull. 47, U. S. Nat. Mus. 44, pi. V, 



fig. 19, 1896. 



