520 PROCEEDINGS OF THE ACADEMY OF [Oct., 



all narrower than their interspaces and last few broken up into spots. 

 Fins all pale. Dorsal Avith large jet-black blotch anteriorly at 

 basal half of fin, and distal portion with three transverse pale dusky 

 streaks, uppermost terminal. Anal with 3 transverse pale dusky 

 streaks. Iris slaty. 



Length 30 mm. 



Type, No. 39,156, A. N. S. P. Tributary of the Madeira River, 

 near Porto Velho, Brazil. January or February, 1913. Edgar A. 

 Smith. 



Also Nos. 39,157 to 39,186, A. N. S. P., same data, paratypes. A 

 number of these show: Head 2| to 2f ; depth 2f to 3; D. ii, 8 

 or II, 9; A. ii, 8 or ii, 9; scales 38 to 40 in lateral series to caudal 

 base, and sometimes 1 or 2 more on latter; 18 or 19 scales trans- 

 versely between dorsal and ventral origins; 12 to 16 predorsal scales; 

 snout 3f to 3f in head, measured from upper jaw tip; eye 3i to 3|; 

 mouth width 3i to 3J; interorbital 3i to 3^; length 26 to 30 mm. 



This species is apparently related to Curimatus vittatus Kner,^ 

 though that species is without the black dorsal blotch and has the 

 scales much smaller (56). 



{Tiypt?^ tiger, with reference to the dark stripes on the back.) 



PROCHILODIN.E. 



Prochilodus pterostigma sp. nov. Fig. 3. 



Head 3f; depth 3|; D. iii, 9, i; A. iii, 7, i; P. i, 12; V. i, 7; 

 scales 44 in 1. 1. to caudal base, and 2 more on latter; 7 scales above 

 1. 1.; 6 scales below 1. 1. to ventral origin; 5 scales below 1. 1. to anal 

 origin; 16 predorsal scales; head width IfV in its length; head 

 depth at occiput 1^; snout 3|; eye 3|; mouth width 3; maxillary 4; 

 interorbital 2f; first branched dorsal ray lyV; first branched anal 

 ray If; least depth of caudal peduncle 2f ; pectoral If; ventral If. 



Body moderately long and compressed, deepest at dorsal origin, 

 back slightly elevated, and edges all more or less convex. Posterior 

 half of predorsal with slight median keel extending to dorsal origin. 

 Upper and lower surfaces of caudal peduncle with slight median 

 keel. On each side of preventral a slight or obsolete keel extending 

 to origin of fin. Caudal peduncle moderately compressed, least 

 depth about 1^ its length. 



Head moderate, compressed, lower profile a little more inclined 

 and convex in front than upper, and nearly level sides not con- 



1 Curimatus (Anodus) mltatus Kner, Denk. Ak. Wiss., Wien, XVII, 18.5.5, p. 

 139, PI. 1, fig. 1. Rio Guapore and Rio Negro. 



