244 MR. C. TATE REGAN ON THE 
4. PANAQUE NIGROLINEATUS. 
Chetostomus nigrolineatus Peters, Monatsb. Ak. Berl. 1877, p. 471; Steind. Denkschr. Ak. Wien, 
xliv. 1881, p. 7. 
Panaque nigrolineatus Kigenm. & Eigenm., Proc. Cal. Ac. (2) ii. 1889, p. 44, and Oce. Pap. Cal. Ac. 
i, 1890, p. 426. 
Depth of body 33 times in the total length, length of head 24 times. Head 1§ times 
as long as broad and 12 times as long as deep. Diameter of eye 7} times in the length 
of head, interorbital width 12 times, length of snout 14 times. Both jaws with about 
8 teeth on each side. Snout narrowed anteriorly; supraoccipital elevated and arched, 
with a nearly straight transverse posterior edge ; interoperculum armed with some slender 
spines, the longest equal in length to the diameter of eye. Scutes spinulose, those of 
the caudal peduncle carinate, 25 in a longitudinal series, 7 between dorsal and adipose 
fin, 12 between anal and caudal; supraoccipital entirely bordered posteriorly by a single 
scute ; lower surface of head and abdomen completely covered with small granular 
scales. D.I 7; length of base of dorsal nearly equal to its distance from caudal. 
A. 14. Pectoral spine extending to middle of ventral. Caudal obliquely truncate. 
Caudal peduncle twice as long as deep. Head, body, and fins with undulating longi- 
tudinal dark brown stripes, which are about as broad as the light interspaces 
separating them. 
Total length 210 mm. . 
One specimen: Goyaz; Venezuela. 
5. CILETOSTOMUS. 
Hypostomus (part.) Cuv. & Val. Hist. Nat. Poiss. xv. p. 489 (1840). 
Chetostoma Tschudi, fauna Peruana, Pisce. p. 25 (1846). 
Chetostomus Kner, Denkschr. Ak. Wien, vii. 1854, p. 256 ; Bleek. Ned. Tijd. Dierk. i. 1865, p. 78; 
Giinth. Cat. Fish. v. p. 240 (1864) (part.) ; Eigenm. & Eigenm. Occ. Pap. Cal. Ac. i. 1890, 
p. 441 (part.). 
This genus is distinguished from Ancistrus by the snout, which has a swollen naked 
margin. D. I 7-10. A. I 3-5. Vertebre 54+8-+14 in C. brevis, 549414 in 
UC. anomalus. 
All the species agree in having the head devoid of ridges or prominences, the supra- 
occipital and interorbital regions being flat, the sides evenly convex. The snout is 
broad and rounded; its naked margin is of moderate width and unprovided with 
tentacles. The mouth is very wide ; the barbels are smal] or rudimentary. ‘The scutes 
are spinulose, not carinate; the lower surface of the head and the abdomen are 
naked. 
Andes, extending into Panama and Venezuela. 
