FISHES OF THE FAMILY LORICARIID. 251 
operculum armed with 4—5 spines. 24-25 scutes in a longitudinal series, 7 between 
dorsal and adipose fin, 10 between anal and caudal. D. I 8, the first ray equal to 
3 the length of head, the last + as long; length of base of dorsal equal to its distance 
from the middle of the spine of the adipose fin. A.15. Pectoral spine extending 
to anterior 3 of ventral or beyond. Caudal obliquely truncate or very slightly 
emarginate. Caudal peduncle 24-23 times as long as deep. Brownish; a small 
dark spot at the base of each dorsal ray ; caudal with small dark spots on the rays. 
Total length 110 mm. 
Three specimens from Villeta, Colombia, collected by Mr. Kay Thomson. 
14. +CH&TOSTOMUS NUDIROSTRIS. 
Chetostomus nudirostris Liitk. Vid. Medd. 1874, p. 207; Steind. Denkschr. Ak. Wien, xliii. 
1881, p. 120, pl. v. fig. 2. 
Evidently closely allied to the preceding species, but with 6-8 interopercular spines, 
23 scutes in a longitudinal series, I 7 dorsal, and I 4 anal rays. 
The type, from Valencia, Venezuela, is 95 mm. in total length. 
15, Cuzrostomus Microps. (Plate XIV. fig. 3.) 
Hypostomus erinaceus (non Cuv. & Val.) Giinth. Proc. Zool. Soe. 1859, p. 420. 
Chetostomus microps Giinth. Cat, Fish. v. p. 250 (1864) ; Steind. Denkschr. Ak. Wien, xlvi. 1882, 
p. 23; Bouleng. Proc. Zool. Soc. 1887, p. 277. 
Depth of body 5} times in the total length, length of head about 3 times. Head 
as broad as long and twice as long as deep. Diameter of eye 8-10 times in the length 
of head, interorbital width 32-3? times, length of snout 13 times. Interoperculum 
armed with 10-15 spines. 25-24 scutes in a longitudinal series, 5 between dorsal and 
adipose fin, 9-10 between anal and caudal. D.I9 (rarely I 10); the first ray equal 
to 3 the length of head, the last # as long; length of base of dorsal equal to its 
distance from caudal. A.I3. Pectoral spine extending to or a little beyond base of 
ventral. Caudal peduncle twice as long as deep. Brownish ; fins with dark spots or 
bars, a black spot at base of first dorsal ray. 
Total length 80 mm. 
Twelve specimens from Ecuador. 
6, XENOCARA, gen. nov. 
Hypostomus (part.) Cuv. & Val. Hist. Nat. Poiss. xv. p. 489 (1840), 
Ancistrus (part.) Kner, Denkschr, Ak. Wien, vii. 1854, p. 272. 
Ancistrus (non Gill) Bleek. Ned. Tijd. Dierk. i. 1863, p. 77; Eigenm. & Eigenm. Occ. Pap. Cal. 
Ac. i. 1890, p. 444. 
Chetostomus (part.) Giinth. Cat. Fish. v. p. 240 (1864). 
This genus is distinguished from Ancistrus by the snout with a naked margin, and 
