NATURAL SCIENCES OP PHILADELPHIA. 131 



Description of HYPOBHAMPHTJS, a New Genus of Fishes allied to Hemi- 



rhainphus, Cuv. 



BY THEO. GILL. 



All those species of fishes which resemble in external form the Esox Brazili- 

 tfisis of Linnaeus, and for which Cuvier framed the genus Ilemirhamphus, have 

 been described as having a straight band of short, granular and equal teeth in 

 each jaw.* Such is the character given to the genus by Valenciennes, in the 

 nineteenth volume of the " Histoire Naturelle des Poissons," where twenty- 

 seven species are referred to it. This character is also repeated in many of the 

 specific descriptions, and many of the species are distinguished by the more or 

 less small size of the teeth. Had any other form or system of dentition existed, 

 it could therefore scarcely have been overlooked by the distinguished French 

 naturalist. It is with much pleasure that I now submit to Ichthyologists the 

 description of a fish which resembles in almost every feature, the known species 

 of Hcmirhamphus, but which have in each jaw a band of distinctly tricuspidate 

 small teeth. Two specimens are in the collection made by the author, at the 

 island of Barbadoes. Owing to an unfortunate accident, the specimens are in 

 poor condition the scales being mostly rubbed off and the fins more or less 

 broken. I am unable, therefore, to furnish at present as full a discription as 

 could have been wished. 



IIyporhampihts Gill. 



Body elongated, very slowly decreasing in height to the dorsal. Scales large, 

 each with a subcentral nucleus and delicate concentric stria;. Head elongated, 

 conical in profile, broad and flattened above. Lower jaw forming an elongated, 

 slender and depressed bill. Upper jaw short and acutely rounded. Teeth small, 

 distinctly tricuspidate, and with the median cusp largest, in a moderate band 

 on each jaw. Dorsal and anal fins posterior and opposite each other, each 

 oblong and simple. Caudal fin moderate, emarginate. Pectoral fins moderate. 

 Ventral fins subcentral, small or moderate. Ventral carina distinct on each 

 side. Tongue thiD, moderate, rounded anteriorly, with parallel sides, and with 

 a median groove, free before and on the sides. 



H. tricuspidatus, Gill. The greatest height equals an eleventh of the 

 extreme length, from the point of the lower jaw to the end of the caudal fin ; 

 the greatest breadth exceeds three-fifths of the height. The head, inclusive of 

 the lower jaw, forms more than three-tenths of the extreme length. The lower 

 jaw, from the tip to the corner of the mouth, constitutes a fifth of the same 

 length, and is five times larger than the upper jaw. The radial formula ap- 

 pears to vary. In a small specimen it is as follows : D 14, A 17, 'C 4, I 6, 7, 

 14, P 11, V 6. 



In a large one D 15, A 16, P 10. 



They are both too much damaged to retain the true colors. The broad sil- 

 very band is present as usual, and widest posteriorly. The upper part of the 

 dorsal is blackish. 



* I have not been in a position to consult the u Catalogue of Malayan Fish," 

 in the eighteenth volume of the Journal of ihe Asiatic Society of Bengal, where 

 Cantor has described a " Ilemirhamphus tridentifer." That species may possibly 

 belong to the genus now described, although the teeth of Ilyporhamphus would 

 be very improperly compared to tridents. The specific name may, however. 

 only allude to the three denticles of each tooth. 



1859.] 



