THE CATFISHES OF VENEZUEiLA — SCHULTZ 201 



short, 3 to 3)5 in the head, smooth on all sides and about two-thirds 

 the length of the branched rays of the dorsal fin; posterior margins 

 of pelvic fins rounded, of the pectoral truncate or a little rounded, 

 the fleshy tip of the pectoral spine reaching beyond the longest 

 branched ray; adipose fin with short base, the tip of adipose extending 

 beyond base and free; the caudal fin changes remarkably with age, 

 in specimens 20 to 40 or 50 mm. in standard length, the upper lobe 

 longest and separated from the lower lobe by short rays, the caudal 

 fin being deeply emarginate; but in a little larger specimen the 

 caudal fin has rounded upper and lower lobes with the middle rays 

 shorter, the fin being a little concave; in the largest specimens and 

 some about 80 mm. and longer the caudal fin being evenly rounded; 

 anal fin rounded; maxillary barbel reaching past head but not quite 

 to opposite dorsal origin; posterior mental barbel reaching a little 

 past the pectoral insertion; anterior mental barbel short, reaching a 

 very little past a vertical line through rear margin of eye; pelvics 

 not quite reaching to anal origin, and pectorals reaching about three- 

 fourths the way to pelvic insertion; the larger specimens as well as 

 some of the smaller ones are profusely covered all over the dorsal 

 and lateral surfaces of the head with minute papillae called "hair- 

 like filaments" by Eigenmann for villosus. 



Color. — In large adults the upper parts are blackish to dark brown, 

 ventral surfaces brownish mottled, and sides and dorsal surfaces 

 sometimes dark spotted, almost obscured; the large specimens, when 

 preserved, have a thick coat of mucus covering the color pattern; 

 specimens 50 to 60 mm. in standard length have the following color 

 pattern, which remains more or less apparent in even a few of the 

 largest specimens: A pale bar across occiput; margins of gill mem- 

 branes pale; usually a pale spot at origin of dorsal and another at 

 origin of adipose fins; a pale bar on middle of length of side of body 

 just behind base of caudal fin and extending directly upward and 

 sometimes more or less confluent with a small white spot in middle to 

 base of posterior rays of dorsal fin; another pale blotch on side under 

 adipose fin; sometimes basal part of posterior anal rays with pale 

 blotch; a small white blotch on both upper and lower edges of caudal 

 peduncle; outer margins of all the fins white, remainder black or 

 mottled with black and white; the caudal fin is variable, usually with 

 a wide white margin posteriorly, then spotted or mottled with black 

 and white, or it may be all white as in the specimens from the Rio 

 Tachira and one from the Motatan system; in some of the larger 

 specimens just inside the wide pale band the caudal fin may have a 

 wide blackish band somewhat broken by white spots. The above 

 color pattern becomes obscured in the largest specimens, and its place 

 is taken by a spotted or mottled pattern; the white margins to the 

 fins remain distinct at all sizes. 



