THE CATFISHES OF VENHZUEIjA — SCITULTZ 291 



has pale tips to the upper and lower caudal lobes; the middle rays at 

 tips are slightly blackish, interradial membranes of caudal with black 

 pigment; a somewhat diffuse yet distinct dark streak along midsides; 

 traces of four dark saddles on back, one in front of dorsal, the second 

 at front of dorsal, third at rear of dorsal, fourth through adipose base 

 and on caudal peduncle; pectoral spines blackish above; pelvics plain 

 like body; the conspicuous black spot between dorsal spine and first 

 branched ray is present but smaller, then less distinct dark spota 

 occur on the naked areaof bcdy between the bases of each soft dorsal 

 ray, the pigment extends a trifle on the base of the interradial mem- 

 branes; membranes between soft dorsal rays with five or six dark spots, 

 the rays pale 



Named tachiraensis for the river in which it was taken. 



Remarks. — This new species may be distinguished from all other 

 species of Chaetostoma by the small dermal fold or keel at rear tip of 

 the supraoccipital, this keel about equal in length to diameter of 

 pupil. Fowler (Proc. Acad. Nat. Sci. Philadelphia, vol. 91, p. 238, 

 figs. 28, 29, 1940) describes C. furcata from Peru as having a bony 

 protuberance at rear tip of supraoccipital, but in tachiraensis this is 

 a dermal keel. C. furcata has I, 4 anal and I, 7 dorsal rays, while the 

 new species has I, 5 and I, 8 rays, respectively. The color pattern of 

 small dark spots anteriorly on head and with the pigment spot on the 

 interradial membranes of the dorsal instead of on the rays is char- 

 acteristic of this new species. The species most closely related to 

 tachiraensis is Fowler's C. milesi (Notulae Naturae, No. 73, p. 2, figs. 

 1-5, 1941) described from Honda, Colombia. This species is repre- 

 sented by three specimens in U.S.N.M. No. 116467, measuring 64 to 

 89 mm. in standard length, from the Magdalena River, Honda, 

 Colombia. Regan's species C. thomsoni (Trans. Zool. Soc. London, 

 vol. 17, pt. 3, p. 250, pi. 14, fig. 2, 19C4), from Villeta, Colombia, is 

 very similar to C. milesi Fowler. However, both of these species 

 difi'er in color; the dorsal fin of C. tachiraensis has the color spots on 

 the membranes of the dorsal instead of on the rays as in C. thomsoni, 

 there is a lateral dark band on tachiraensis, but in C. milesi there are 

 about four rows of small dark spots along the sides; all three speci- 

 mens of milesi before me agree with Fowler's figures, except there are 

 no spots on the dorsal membranes. The caudal fin is much less con- 

 cave in milesi and thomsoni than in tachiraensis, it is almost forked 

 in the latter. 



CHAETOSTOMA MILESI Fowler 



Chaetostoma milesi Fowler, Notulae Naturae, No. 73, p. 2, figs. 1-5, 1941 (Honda, 

 Colombia). 



U.S.N.M. No. 121051, 2 specimens, 98 and 130 mm., from Rfo Gudrico (Orinoco 

 system) and tributaries between San Sebastidn and San Casimiro, Estado de 



