tit PROCEEDINGS OF THK. ACADEMY OF 



Scales minute, cycloid, regularly imbricated. * 



Head little longer than high, ascending from the nape to the interorbital 

 region, in front of which the profile is very steep ; below plane. Eyes prom- 

 inent, separated by a narrow furrow. Border of skin above mouth with a 

 triangular flap on each side of the middle. Scales minute, like those of the 

 body. 



Mouth moderate, with the periphery semioval, the supramaxillars termi- 

 nating under the pupils. Lower jaw most advanced. Upper lip very wide, 

 especially at the sides ; lower free only near the angles of the mouth. 



Teeth erect in both jaws, uniserial, acutely conic ; above a large median 

 one in front, and one on each side, between which and the former small teeth 

 like those of the sides intervene ; in the lower jaw two large teeth in front, 

 separated by a wide, smooth interval, and on the sides a row of small ones. 



Branchial apertures small, in front of the lower half of the arm. 



Branchiostegal rays five. 



Dorsal fins separated by a short interval ; the spinous above the pectoral 

 tin, higher than long, with ten to fifteen slender, divergent spines : the second 

 oblong, and with about twelve rays. 



Anal fin short and low, under the middle of the second dorsal, with ten or 

 eleven rays. 



Caudal fin behind convex at the upper half, at the lower half very rapidly- 

 curved forwards. 



Pectoral fins inserted on large free arms narrowed towards their bases, 

 the fin nearly or quite scaleless, with the upper rays rapidly increasing in 

 a curved line to the eighth, and the lower gradually shortened, their end* 

 defining a moderate curve. 



Ventral fins thoracic, under the bases of the arms, separated by a narrow, 

 triangular area, which ends between their inner rays in a point ; each has a 

 spine and five rays increasing toward the inner, their ends describing a 

 curve. 



Type Periophthalmus Kcelreuteri BL, Schn. 



Distinguished for the size of the scales, form of the head, dentition, size of 

 branchial apertures, form of anal fin, free arms, and persistent, separation of 

 the ventral fins. 



Note o tiie genera of HEMLRHAMPHIlsr^:. 

 BY THEODORE GILL. 



Valenciennes, in the nineteenth volume of the " Histoire Naturelle des Pois- 

 sons," has especially alluded in many cases to the dentition of the various 

 ipeciea of the genus Hemirhamphus, describing the teeth as " very short, blunt 

 and conic, or rather granulated," (//. Brownii C. et V. lix., p. 16,) finer in some, 

 coarser in others ; in the observations on the genus, the following characters 

 are given : " Les deux machoires sont garnies d'une bande 6troite de petites 

 dents courts, grenues et gales," (C. et V. xix., p. 2.)" II faut aussi remarquer 

 que les dents restent toujours petites et egales, tandis qu'elles s'allongent, 

 comine ou le sait, dans les orpines." Trusting in the correctness of Valen- 

 ciennes, I formerly proposed a new generic designation for a species of the 

 tribe, with tricuspid teeth, found at the island of Barbados. As subsequent 

 examination of numerous specimens from the West Indies and elsewhere has, 

 however, failed to discover a dentition among the typical Hemirhamphi like 

 that described by Valenciennes, I am compelled to believe that he is in some 

 cases, if not in all, incorrect; after the arrival at this conclusion, it is easy 

 to believe that the Hyporhamphus tricuspidatus may perhaps be identical with 

 the Hemirhamphus Richardi of Valenciennes, the teeth of which are, however, 

 described as being finer and in a wider band than in any other. Again, aB the 



[Sept. 



