Edentulous Genera of Curimatmm. 425 



3i in head. Silvery, with purple and greenish reflections. Lateral 

 scales with a frosted appearance. Head 4; depth 3^. D. 11; A. 9^. 

 Scales 5-39-5. 



18. CURIMATUS PliUMBEUS sp. nOT. 



Types, eight specimens, .053-.13 m. Lake Hyanuary; Thayer Exped. 



No. 20,348, 15 specimens, .075-.095 m. Lake Hyanuary ; Navez. 



Closely related to C. spilurus and C. magdalence. 



Elongate slender. Preventral region flat, without distinct lateral 

 keels ; postventral region with indistinct median and lateral keels. A 

 few predorsal scales keeled, region before them flattish. Scales partly 

 dentate, partly cycloid. Lateral scales with widely diverging keels. 

 Caudal lobes naked. 



Profile slightly convex, not very steep. 



Eye 3-3i in the head, 1^ in the interorbital, which is less than the 

 depth of the head at the pupil. 



Air-bladder extending to the anal. 



Origin of dorsal little nearer to tip of snout than to tip of adipose fin. 

 Pectorals not reaching to ventrals ; ventrals about to vent, their origin 

 equidistant from tip of snout and base of caudal. Caudal lobes long, 

 pointed, equal, and much longer than the head. 



Plumbeous with silvery and bluish reflections ; a silvery lateral band ; 

 no dark caudal spot. 



Head 3| ; depth 3^-3^. D. 13 ; A. 10-11. Scales 5-37-5. 



Eight specimens from Obidos may also be referred to this species. 



19. CURIMATUS NAQEIill. 



Curimatusnagelii Steind., '81b, 11 (Rio Janeiro), 



20. CURIMATUS LEUCOSTICTUS sp. nov. 



Types, No. 787, one specimen, .11 m. to base of caudal. Rio Negro; 

 J. C. Fletcher. 

 No. 20,315, one specimen, .075 m. to base of caudal. Lago 

 Alexo ; S. V. R. Thayer. 

 Elongate, rather slender. Preventral region flat, with a median series 

 of scales and obtuse keels laterally ; postventral region with an obtuse 

 median keel. Predorsal region narrow, with a median keel ; postdorsal 

 region with obtuse lateral keels. 



Profile somewhat depressed at the occiput in the larger specimen. 



Eye with narrow adipose lids, f in snout, 2f in head, 1^ in interorbital. 



Scales of the back and breast pectinate, those of the sides more weakly 



ctenoid. Base of caudal rays scaled. 



Highest dorsal ray shorter than the head. Anal emarginate, the tip 



