EIGENMANN: the freshwater fishes of BRITISH GUIANA 343 



very narrow, not reaching the caudal; no caudal spot. Dorsal scales outlined with 

 dusky. Top of head very thickly covered with chromatophores. Fins all a little 

 dusky. Sides silvery, iridescent. Caudal peduncle to in front of adipose, the 

 adipose and caudal (except the lobes) very rich cherry-red. Caudal lobes, anal, 

 and dorsal canary-yellow. 



Dermatocheir Durbin. 

 Dermatocheir Durbin, Ann. Carnegie Museum, VI, 1909, 55. 



This genus differs from its nearest relative, Hyphessobrycon, in having an archaic 

 pectoral like Archicheir. The pectoral consists of a fleshy lobe, surrounded by a 

 fringe of filaments. 



Type, Dermatocheir catablepta Durbin. 



204. Dermatocheir catablepta Durbin. 

 Dermatocheir catablepta Durbin, Ann. Carnegie Mus., VI, 1909, 55. — Eigenmann, 



Repts. Princeton Univ. Exp. Patagonia, III, 1910, 437. 



Type unique, 18 mm. Tumatumari, above the falls. (Carnegie Museum 

 Catalog of Fishes No. 1198.) 



Head 3.5; depth 3.8; D. 11; A. 20; scales 5-33-3; eye 2.5 in the head; inter- 

 orbital very slightly greater than the eye, 2.2 in the head. 



Humeral spot vertically elongate, very faint. No caudal spot, but a few 

 chromatophores at the base of each caudal lobe. Lateral stripe very dim. Scales 

 of the back outlined with dusky. Fins without pigment. 



Creatochanes Giinther. 

 Creatochanes GiJNTHER, Catalogue, V, 1864, 318, 329. 



Type, Salmo melanurus Bloch. 



Elongate, spindle-shaped fishes, but slightly compressed, reaching a length of 

 157 mm. The species are very similar and have the following characters in common : 

 premaxillary with a distinct antero-posterior extent meeting the anterior portion 

 of the maxillarj^ at a nearly right angle; maxillary long, slipping under the first 

 suborbital, as well as under the preorbital, its anterior margin greatly arched above, 

 straight, or nearly so, below; mouth large, the lower jaw freely movable; tongue but 

 little free, fleshy. Snout and maxillary much more than half the head in length. 



Lower jaw included, with five or six large equal teeth in front, each with a 

 long median and several minute lateral cusps, the lateral teeth somewhat recurved 

 and followed by a series of minute teeth. Premaxillary with five or six multicuspid 

 incisor teeth in the inner row; teeth of the outer row narrower; maxillary with two 

 multicuspid teeth. 



