FISHES OF THE FAMILY LORICARIID#, 255 
a 
Interoperculum armed with 10-12 spines, the longest 1 the length of head. 
23-24 scutes in a longitudinal series, 6-7 between dorsal Anal ctpea: fin, 11 between 
anal and caudal. D. I 7, the first ray 3-8 the length of head, the last ray, when laid 
back, reaching the spine of the adipose fin or the scute preceding it; length of base 
of, dorsal equal to its distance from posterior 1 of spine of adipose fin. A. I 4. 
Pectoral spine extending to anterior } of ventral. Caudal obliquely truncate, 
the lowest ray {-} the length of head. Caudal peduncle 21-23 times as long 
as deep. Brownish; head and anterior part of body with light spots which are 
separated by a network of dark lines; fins dusky, the dorsal with darker undulating 
cross-bars, 
Total length 125 mm. 
Four. specimens: Guiana. 
5. XENOCARA HOPLOGENYS. 
Chetostomus hoplogenys Giinth. Cat. Fish. v. p- 247 (1864). 
Chetostomus leucostictus Giinth. t.c. p. 248. 
Chetostomus alga Cope, Proc. Ac. Philad. 1871, p. 287, pl. xv. fig. 3. 
Chetostomus malacops Cope, t.c. p. 287, pl. v. fig. 2. 
Chetostomus tectirostris Cope, t.c. p. 288, pl. xv. fig. 2. 
Ancistrus hoplogenys Kigenm. & Eigenm. Proc. Cal. Ac. (2) ii. 1889, p. 48, and Occ. Pap. Cal. Ac. 
1. 1890, p. 448. 
Ancistrus leucostictus Kigenm. & Eigenm. |. c. and t. c. p. 447. 
Depth of body about 5 times in the total length, length of head 23-22 times. 
Head 1{-1§ times as long as broad and twice as long as deep. Diameter of eye 
5-6 times in the length of head, interorbital width 2-21 times, length of snout 
1§-2 times. Length of mandibular ramus 34-3} times in the interorbital width. 
Snout with tentacles. Interoperculum armed with 7—10 spines, the longest {—! the 
length of head. 23-24 scutes in a longitudinal series, 7 between dorsal and adipose 
fin, 10-11 between anal and caudal. OD. | 7, the first ray $3 the length of head, 
the last ray, when laid back, reaching the spine of the adipose fin; length of base of 
dorsal equal to its distance from posterior 3 or tip of spine of adipose fin. A. I 4. 
Pectoral spine extending to base (young) or anterior § (adult) of ventral. Caudal 
obliquely truncate, the lowest ray nearly (adult) or quite (young) as long as the 
head, Caudal peduncle 24-24 times as long as deep. Brownish; fins dusky; 
small white dots on head, body, and fins, which are fewer and better defined in the 
young; dorsal with a blackish spot at the base of the first interradial membrane. 
Total length 145 mm. 
Kight specimens: Guiana; R, Amazon; R. Paraguay. 
VOL, XVII.—PART 11. No. 9.—October, 1904. 2M 
