324 NEW YORK STATE MUSEIUM 



going in large schools, but usually remaining near sliore, feeding 

 chiefly on green algae. Size comparatively small. 



■ 161 Hyporhamphus roberti (Cut. & Yal.) 



Halfheak 



EemirJiamplnts roberti Cuvier & Valencienkes, Hist. Nat. Poiss. XIX. 24, 



1846, Cayenne; Gunther, Cat. Pish. Brit. Mus. VI, 2^3, 1866; Meek & 



Goss. Proc. Ac. Nat. Sci. Phila. 223, 1SS4; Beax, Bull. U. S. F. C. 



YII, 147, pi. Ill, fig. 16, 1SS8; 19th Kept. Commrs. Fish. N. Y. 274, 



1890. 

 Eemirhamplius unifasciatvs Jordan «&: Gilbert, Bull. 16, U. S. Nat. Mus. 



376, 1883. 

 Hyporhamphus roberti Jordan & Evermann, Check-List Fish. N. A. 321, 



1896; Bull. 47, U. S. Nat. Mus. 721, 1896, pi. CXYII, fig. 312, 1909; 



Bean, 52d Ann. Kept. N. Y. State Mus. 100, 1900. 



Body compressed, elongate, its greatest depth one eighth of 

 total length to caudal base, its greatest width equal to post- 

 orbital part of head; caudal peduncle short and deep, its least 

 depth equal to eye. From eye to end of upper jaw equals one 

 third the distance from end of upper jaw to hind margin of 

 opercle. Head includjng lower jaw three eighths of total 

 length without caudal, without projecting part of lower jaw 

 two elevenths of the same; eye equal to interorbital width, 

 about one eighth of length of head (one fourth of head to end 

 of upper jaw) ; projecting part of lower jaw a little longer than 

 rest of head; dorsal origin over the anal origin, 34 rows of 

 scales between it and the nape, base of dorsal equal to eye and 

 postorbital jiart of head combined, longest dorsal ray equal 

 to postorbital jjart of head, last dorsal ray less than one half the 

 longest, and about two thirds of the eye; anal base slightly 

 shorter than dorsal base, longest anal ray slightly longer than 

 postorbital part of head, last anal ray one half of eye; ventral 

 origin about midway between eye and base of caudal, the fin 

 about as long as the postorbital part of head; pectoral base 

 high, on the level with the eye, the fin about as long as upper 

 jaw and eye combined; caudal fin symmetrically forked, the 

 middle ravs two thirds as long as the external, and nearly twice 

 as long as the eye (from end of scales only a little longer than 

 the eye); dorsal and anal fins densely scaled; lateral line com- 



