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 dusk}'. Fins without pigment. 



Creatochanes Gtinther. 

 Creatochanes Gunther, 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 maxillary 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. 



