EIGENMANN: THE FRESHWATER FISHES OF BRITISH GUIANA 275 



Heavy, tapering rapidly to the conical snout. Lower caudal lobe longer than 

 the upper. 



Dark above, lighter below; a black band from snout to end of middle caudal 

 rays, a narrower one parallel with it from the occiput to the base of the upper caudal 

 rays; a blackish band across the upper part of the anterior dorsal rays. 



Hemiodus Muller. 

 Hemiodus Muller, Monatschr. Akad. Wiss. Berlin, Juni, 1842, 324. 

 Hemiodopsis Fowler, Proc. Acad. Nat. Sci. Phila., 1906, 318 (microkpis). 



Type, Hemiodus crenidens Muller = Hemiodus unimaculatus (Bloch). 



Teeth in the upper jaw only, pluricuspid, in a horseshoe-shaped series; mouth 

 inferior; gill-membranes free from each other and from the isthmus; fontanels 

 large; scales below the lateral line of the same size as those above it. 



Key to the Guiana Species of Hemiodus. 

 a. Sides with three black cross-bands; a black spot on the caudal peduncle, continued to the end of the lower 



caudal lobe; upper caudal lobe with a weaker "black band quadrimaculatus. 



ua. A black spot on the middle of the sides, half-way between dorsal and adipose, and a black band extending 

 from it to the tip of the lower caudal lobe semitaeniatus. 



132. Hemiodus quadrimaculatus Pellegrin. (Plate XXXVI, fig. 2.) 



" Wuranali " of the Wacusi Indians. 



Hemiodus quadrimacidatus Pellegrin, Bull. Mus. d'Hist. Nat., XIV, 1908, 344 



(Camopi R., Fr. Guiana). — Eigenmann, Repts. Princeton Univ. Exp. Pata- 

 gonia, III, 1910, 423. 



One specimen, 110 mm. Tukeit. (C. M. Cat. No. 1926.) 



Three specimens, 55-70 mm. Amatuk. (C. M. Cat. No. 1927; I. U. Cat. 

 No. 12187.) 



Thirty-four specimens, the largest 81 mm. Tumatumari, in pools above the 

 cataract. (C. M. Cat, No. 1928a-e; I. U. Cat. No. 12188.) 



Six specimens, 57-125 mm. Crab Falls. (C. M. Cat. No. 1929a and 1930; 

 I. U. Cat. No. 12189.) 



A conspicuously marked species, evidently closely related to, if not identical 

 with, Hemiodus quadrimaculatus Pellegrin. 



Head about 4; depth 4-4.4; D. 12; A. 10; scales 7 or 8-44 to 46-4 or 5. 

 Eye 1.3 in snout, 3.3 in head, 1 in interorbital. 



Dorsal and ventral outlines equally arched, the snout pointed, projecting 

 considerably; preventral area broad, with a regular median series of scales. 



Twenty to twenty-four teeth in the upper jaw. 



