Jordan and Everniann. Fishes of North America. 45 



Subgenus SPHYRNA. 



2. SPHYUXA ZYCJ.EXA, (Linnajus). 



(HAMMER-HEADED SHARK.) 



Head truly hammer-shaped; width of head about twice its length; 

 length of hinder margin of hammer nearly equal to its width near the 

 eye; nostril close to eye, prolonged into a groove which runs along nearly 

 the whole front margin of head; first dorsal large; second quite small, 

 smaller than anal; pectoral rather large. Color gray. A large voracious 

 shark, reaching a length of 15 feet or more, found in all warm seas; occa- 

 sional on our coasts from Cape Cod and from Point Coucepcion south- 

 ward. (i>yaiva, Zygoma, the ancient name, from vyuv, yoke.) (Eu.) 



Sy/Ki/^ wui'i, Lixx.v.rs, Syst. Nat., Ed. x, 1758, 234, Europe; America. 



S'/nnlns -,,ntU>'HS, Risso, Ichth. Nice., 34, 1810, Nice. 



y.H<j;ut<t itiullcits, STOKER, Fish. Mass., 238,1867. 



)%r .:.//;/.[, JORDAN & GILBERT, Synopsis, 25,1883. 



Xiiymm l>:iri,ii, LORD in GRIFFITH, Animal Kingdom, x, 640, 1834, New Holland. 



fyijicna w.burcuutu, SroKEB, Proc. Bost. Soe. Nat. Hist., 1848, 70, Cape Cod. 



Family XIII. ALOPIID^E. 

 (THE THRESHER SHARKS.) 



Body moderately elongate, the anout rather short; mouth crescent- 

 shaped, teeth equal in both jaws, moderate sized, flat, triangular, not 

 serrated; the third tooth of the upper jaw on each side much smaller than 

 the others; gill openings moderate, the last one above the root of the 

 pectorals; no nictitating membrane; spiracles just behind eye, minute or 

 absent; first dorsal large, midway between pectorals and ventrals; second 

 dorsal and anal very small; caudal fin exceedingly long, about as long 

 as the rest of the body, a pit at its root, a notch on the upper lobe near 

 its tip; lower lobe moderately developed; no caudal keel; ventrals rather 

 large; pectorals very large, falcate. A single species, reaching a large 

 size, inhabiting most seas, known at once by the great length of the tail. 

 (Lamnidw, part, Giinther, vin, 393; genus Alopecias.) 



30. ALOPIAS, Rafinesque. 

 (THRESHER SHARKS.) 



.1 /././.<, RAFINESQUE, Caratteri di Alcuni Generi, etc., 12, 1810, (mcicroimis=indpes). 

 IMru.Ku * HENLE, Plagiostomen, 74, 1838, amended orthography. 



The characters of the genus are included above. (uAwrror, a fox, Latin, 

 unices. A. vutyes was known to the ancients as a/Urne/cmf, fox-like). 



63. ALOPIAS VFLPES, (Gmelin). 



(THRESHER; Fox -SHARK ; SWINGLE TAIL; LONG-TAIL SHARK.) 



A large shark, abounding in all warm seas, especially in the Mediter- 

 ranean and Atlantic. It is also frequently taken on our Pacific coast. 



(n<7/?es,fox.) (Eu.) 



