418 A Revision of the 



2. CURIMATUS MfiYERI. 



Curimatus meyeri Steind., '82a, 11, pi. I., fig. 4(Huallaga). 



Habitat, Huallaga; Obidos; Manacapuru. 



A single specimen, .10 m. long, from Obidos, and another, .12 m., from 

 Manacapuru, may represent this species. 



Head 3f; depth 3i. D. 13; A. 10. Scales 6-40-?. 



3. CURIMATUS SERP^ sp. nov. 



Types, No. 20,320, four specimens, .065-.075 m. to base of caudal. 

 Serpa; Thayer. 



A beautiful species, related to alburnus, meyeri, and immaculatus, 

 differing in the proportions, scales, etc. 



Elongate slender. Pre ventral region depressed, without lateral keels; 

 postventral region with three indistinct keels. Predorsal region sharply 

 keeled to the occipital crest. Postdorsal region with three indistinct 

 keels. 



Scales cycloid, persistent, their surface with two widely diverging 

 ridges. All the caudal rays thickly covered with scales to near their 

 tip. 



Anterior profile straight, upper profile but little convex. Mouth sub- 

 terminal. Eye 3-3^ in head, l^lf in interorbital, which is equal to the 

 depth of the head at the pupil. 



Dorsal much higher than long, its highest ray longer than the ven- 

 tral, shorter than the head. Anal truncate, the anterior rays much 

 longer. Pectorals not reaching to ventrals, which do not reach the 

 vent. 



Air-bladder extending to middle of anal. 



Light-brown above, silvery below, everywhere with metallic reflec- 

 tions. Dorsal scales with a brownish spot as in meyeri and alburnus. 



Head 3i-31; depth 3. D. 12-13; A. 10-11. Scales 6-39 to 41-5. 



:4. CURIMATUS AI.HURNUS. 



Anodus alburnus M. and T., '45a, 26, pi. IV., fig. 3 (Lake Amucu, British 



Guiana); id. '48a, 633 (Lake Amucu). 

 Curimatus alburnus Kner, '59a, 144 (Rio Guapore; Matto Grosso); Gthr., 

 '64a, 289 (copied); Steind., '76a, 33 (Teffe); id. '79a, 5 (Orinoco near 

 Ciudad Bolivar); id. '81a, 36 (Amazon). 

 Habitat, Northern Brazil and northward. 



About 55 specimens, .13-.22 m. Surinam; Coary; Lake Hyanuary; 

 Rio Negro; Jutahy; Ueranduba; Tefl:e; Manacapuru; Hyavary; Tonan- 

 tins. 



Stout, tapering backward; preventral region fiattened, a median 

 series of large scales^ and bluntly keeled scales in the lateral series; 



