Durbin : The Expedition to British Guiana. 67 



Hyphessobrycon rosaceus sp. nov. 



Type, 35 mm. (No. 1190 Carnegie Museum Catalog of Fishes.) 

 Gluck Island. 



Cotypes, 25 specimens, 19-38 mm. Gluck Island. (C. M. Cat. 

 No. 1 191, a-e\ I. U. Cat. No. 11768.) 



Cotype, 1 specimen, 34 mm. Rockstone. (C. M. Cat. No. 

 1192, a.) 



Distinguished by an intense round black spot on the first seven 

 dorsal rays, the tips of the second and third dorsal rays milk-white. 

 No humeral or caudal spot. Anal 26 or 27. Teeth of the maxillary 

 and premaxillary small, conical, and tricuspid. Eye large. 



Head 3-3— 3f, depth 2.75; D. 11, A. 26 or 27; scales 5-31 to 

 33-3; eye 2.5 in head; interorbitals almost equal to the eye, 2.6 in 

 the head. 



Compressed, head at base of occipital process two-thirds of the 

 greatest depth. Preventral region rounded, without complete series 

 of median scales ; post-ventral region narrow. Predorsal region 

 rounded, without complete series of median scales, slightly keeled. 



Occipital process about one-fifth of the distance from its base to the 

 dorsal, bordered by three scales. Interorbitals somewhat convex. 

 Frontal fontanel triangular, as wide as the parietal and almost equal to 

 the length of the parietals without the occipital groove. Second sub- 

 orbital with a narrow naked margin behind but not below ; third sub- 

 orbital very small. Maxillary equal to the eye; mandible longer than 

 the eye, 2 -f- into the head. Lower jaw included only when the 

 mouth is closed. Snout short ; mouth large. Premaxillary with two 

 or three narrow tricuspid teeth in the outer row and six to eight 

 small tricuspid and conical teeth in the inner row. The two rows 

 of premaxillary teeth not so far apart as in most species of the genus. 

 Maxillary with four to six very small narrowly tricuspid or conical 

 teeth. Dentary with a graduated series of five three- to five-pointed 

 teeth, followed by about eight minute teeth on the side. 



Gillrakers 8+12. 



Scales cycloid, regularly imbricate, no interpolated scales or rows 

 of scales, striae few, variable in number. Anal sheath short, composed 

 of four or five scales covering the base of the first seven or eight anal 

 rays. Lateral line with pores developed on six- or seven scales, 

 slightly decurved. 



Origin of dorsal about half the length of the eye nearer the snout 



