EIGENMANN: the freshwater fishes of BRITISH GUIANA 317 



tooth on each side of each jaw, similar to, but narrower than, those of the inner 

 series; two similar teeth on the maxillary and seven similar ones on each side of the 

 lower jaw; checks narrow, entirely covered by the suborbitals. 



Scales thin, cycloid, deeply imbricate, with few (or more frequently no) radial 

 striaj; caudal and anal naked; lateral line complete, decurrent; dorsal short, its 

 length less than half its height, which is 6.75 in the length; lower caudal lobe the 

 longer, 4.5 in the length; origin of anal under origin of dorsal or a little farther 

 forward; ventrals small, not reaching anal, in contact along their inner margin 

 when closed; pectorals large, directed downward and backward when closed, the 

 tips projecting beyond the ventral profile, not reaching the ventrals; when opened 

 the margins of the pectorals are in one plane. 



Iridescent, the middle caudal rays dusky, otherwise without marking. 



Subfamily Agoniatin^. 

 Agoniates Miiller and Troschel. 



Agoniates Mijller and Troschel, Hor. Ichth., I, 1845, 33 (halecinus). 



Type, Agoniates halecinus Miiller and Troschel. 



Breast trenchant, not expanded; maxillary and mandiljle with a single series, 

 premaxillary with two series of teeth, those of the inner series of the premaxillary 

 tricuspid; a large canine on the mandible on each side anteriorly, received in a 

 groove on the palate; a few minute tricuspid teeth between the anterior canine 

 teeth, a pair of conical teeth within the outer series in front; seven or eight conical 

 teeth on the side of the lower jaw behind the fangs, the third largest; cheeks 

 entirely covered. 



A genus of one species. 



172. Agoniates halecinus IMliller and Troschel. 



Agoniates halecinus Mxjller and Troschel, Horse Ichth., I, 1845, 33, pi. 7, fig. 2 

 (Guiana); in Schomburgk, Reisen, III, 1848, 636 (Cuyuni). — Cuvier and 

 Valenciennes, Hist. Nat. Poiss., 1848, 347.— Gijnther, Catalogue, V, 1864, 

 344.— EiGENMANN and Eigenmann, Proc. U. S. Nat. Mus., XIV, 1891, 57.— 

 EiGENMANN, Repts. Princeton Univ. Exp. Patagonia, III, 1910, 440. 

 Head 4.66 in the length; depth somewhat less than the length of the head; 



A. 30; lateral line 39, silvery. 



This species, which greatly resembles Hydrolycus scomberoides, is known from 



the type only, about 100 mm. long, in the Berlin Museum. 



