412 NEW YORK STATE MUSEUM 



naked; body covered with small, linear, embedded scales, whichi 

 are irregularly arranged; fins scaleless. D. V, I, 20; A, II. I,. 

 20; Y. I, 5; P. I, 16. Top of head ai;id back bluish; sides and 

 lower parts silvery; fins, interopercle and iris yellow. 



The leather jacket inhabits both coasts of tropical America, 

 extending northward to Cape Cod and Lower California; it is 

 very common in the West Indies and the Gulf of Mexico. Rare 

 at Woods Hole, Mass., where only three examples were secured 

 firom 1874 to 1886 in traps and pound nets. At Newport R. I. 

 the species is occasionally seen. The fish is rare in Gravesend 

 bay; an example 9f inches long and 2^ inches deep was secured 

 in John B. De Nyse's pound in the summer of 1896. The fish 

 has no value as food. 



Genus nauorates Rafinesque 



This genus differs from Seriola only in the reduction of 



the spinous dorsal to a few (four or five) low, unconnected 



spines. The young, called Nauclerus and X y s t o p h - 



o r u s , have the spines of the dorsals connected by membrane, 



and a more or less distinct strong spine at the angle of the 



operculum. A single pelagic species widely distributed in the 



open seas. 



206 Naucrates ductor (Linnaeus) 



Pilotfish 



Gasterosteus ductor Linnaeus, Syst. Nat. ed. X, I, 295, 1758, pelagic. 



Scomber ductor Mitchill, Trans. Lit. & Pliil Soc. N. Y. I, 42f4, 1815. 



Nancrates novehoracensis Cuyier &. Valenciennes, Hist. Nat. Poiss. VIII, 

 335, 1831; De Kay, N. Y. Fauna, Pishes, 112, 1842, and figiure of 

 Naucr cites ductor, pi. 74, fig. 235. 



Naucrates ductcr Cuvier & Valenciennes, Hist. Nat. Poiss. VIII, 312, pi. 

 232, 1881; Gunthee, Cat. Fish. Brit. Mus. II, 374, 1860; Jordan & 

 Gilbert, Bull. 16, U. S. Nat. Mus. 443, 1883; Jordan & Evermann, 

 Bull. 47, U. S. Nat. Mus. 900, 1896, pi. CXXXIX, fig. 379, 1900; Smith, 

 Bull. U. S. F. 0. XVII, 97, 1898. 



Naucrates iudiciis Cuvier, Regne Anini. 111. Poiss. pi. 54, fig. 1, 1830'. 



Body fusiform, elongate, moderately thick, its greatest hight 

 one fourth of total length without the caudal, and about equal 

 to length of head, its width equal to three fifths of length of 

 head; least depth of caudal peduncle about equal to long 

 diameter of eye; head subconical, the snout obtuse, length of 



