420 A Revision of the 



Origin of dorsal about midway between tip of snout and tip of adi- 

 pose. Anal emarginate, pectorals not reaching to ventrals, ventrals 

 about to vent. Origin of ventrals midway between tip of snout and 

 base of caudal. Depth of caudal peduncle little more than 2 in head. 



Light brown with silvery and bluish reflections, a plumbeous median 

 band terminating in a black spot at base of caudal. 



Head 2^-4; depth 2^3 (2^ in some specimens according to Giinther). 

 D. 13; A. 10-11. Lat. 1. 33-35. 



6. CURIOTATUS SPILVROPSIS sp. nov. 



Five specimens, No. 20,218, .075-.09 m., collected by Mr. W. James 

 at 19a, have the ventral profile almost straight and the back greatly ele- 

 vated. The back in front of the dorsal is strongly convex and the 

 median series of scales keeled. Preventral surface flat, postventral 

 surface rounded. 



Scales smooth. edged, the ridges scarcely evident. 



Mouth entirely below the level of the orbit. 



Origin of ventrals a little nearer to base of caudal than to tip of snout. 



Caudal spot indistinct. 



Depth 2|-8, otherwise as in C. spilurus. 



Three other specimens, also from I^a, have no caudal spot. 



7. CURIMATUS DORSAL.IS sp. nov. 



Types, No. 20,183, one specimen, .09 m. Coary; L. Agassiz. 



No. 20,210, one specimen, .09 m. Manacapuru; W. James. 



No. 20,241, one specimen, .082 m. Hyavary. 



No. 20,380, one specimen, .09 m. Obidos; Col. Bentos. 



Habitat, Amazon, Solimoens and tributaries. 



Related to C. spilurus. Compressed dorsadiform; preventral region 

 flattened, with a median series of large scales; postventral region with 

 two indistinct lateral keels, the median series of scales arched. Pre- 

 dorsal greatly arched and with a median keel; postdorsal region 

 rounded. 



Scales persistent; the broadly rounded posterior margin crenate; the 

 surface with indistinct longitudihal ridges or none. Basal half of the 

 caudal rays scaled. Pores of the anterior scales of the lateral line im- 

 perfectly developed or wanting. 



Profile greatly arched behind the occiput, and conspicuously depressed 

 at the occiput. Eye 2|-3 in head, 1^-1 f in interorbital. 



Air-bladder terminating in a filiform process which rests against the 

 anterior surface of the first interhaemal. 



Origin of dorsal midway between tip of snout and tip of adipose. 

 Anal short, emarginate. Pectorals not reaching to ventrals, ventrals to 

 vent. Origin of ventrals about equidistant from tip of snout and base 

 of caudal. 



