eigenmann: the FRESHWATER FISHES OF BRITISH GUIANA 293 



Hyaline. Sides with numerous crescents of brown; back with about thirteen 

 cross-bars made up of crescents; in places two opposing crescents form ocelli. A 

 dark band from eye to end of snout; a black bar through the opercle; a deep- 

 seated spot on angle of preopercle; a streak, sometimes broken, backward from eye; 

 an interrupted black line along the ventral surface, concentrated between the 

 ventrals and in front of the anal. Faint markings on dorsal, caudal, and anal; 

 fins otherwise hyaline. 



151. Characidium catenatum Eigenmann. (Plate XXXVIII, figs. 5, 6.) 



Characidium catenatum Eigenmann, Ann. Carnegie Mus., VI, 1909, 40; Repts. 



Princeton Univ. Exp. Patagonia, III, 1910, 428. 



Type, 38 mm. Warraputa. (Carnegie Museum Catalog of Fishes No. 1153.) 



Cotypes, twelve specimens, 32-35 mm. Rockstone sand-bank. (C. M. Cat. 

 No. 1154a-d; I. U. Cat No. 11681.) 



Cotypes, two specimens, 37-38 mm. Crab Falls. (C. M. Cat. No. 1155a; 

 I. U. Cat. No. 11682.) 



A sand-burrowing characin, resembling Ammocrypta pellucida. It stands 

 alone among the species from Guiana in having single-pointed, strictly conical 

 teeth, approaching in this respect Pyrrhulinus. 



Head 4-4.2; depth 6-6.2; D. 10 or 11; A. 8; scales 4-38-3, ten before the dorsal. 

 Eye a little longer than snout, 3.3 in head; bony interorbital about 2 in eye. 

 Teeth conical. 



Pectorals reaching ventrals or not, the tips of the outer rays not thickened; 

 ventrals not to anal ; anal rounded, the fifth ray highest, reaching slightly beyond 

 tip of last, not nearly to caudal; dorsal low, subtruncate, the third ray not quite 

 reaching tip of last; base of dorsal extending half-way to tip of adipose, 7.75 in the 

 length. 



Pellucid in life. Sides of head and body more or less iridescent; a dark stripe 

 from eye to end of snout; about ten dark brown cross-bars, most intense on back 

 and along the lateral line; the centers of the scales of the bars colorless, giving each 

 band a chain-like appearance ; a few chromatophores on the margins of other dorsal 

 scales. A minute, round black spot at base of caudal, surrounded by a hyaline 

 area, which is bounded posteriorly by a faint color-halo; fins otherwise all hyaline. 

 A blackish median line from behind ventrals to the vent. 



