FISHES OF THE FAMILY LORICARIIDZ. 233 
edges slightly raised; supraoccipital with low median elevation ; temporal plate not 
carinate ; interoperculum armed with a few slender spines, the longest equal to the 
diameter of eye. Scutes spinulose, not carinate, 26 in a longitudinal series, 7 between 
dorsal and adipose fin, 12 between anal and caudal. Supraoccipital bordered posteriorly 
by a median scute and by one on each side; lower surface of head and abdomen (in 
the young) naked, except for a granular strip between the pectorals. D.I7, the 
first ray a little shorter than the head, the last 4 as long; length of base of dorsal 
considerably more than its distance from the adipose fin. A. I 4. Pectoral spine 
extending well beyond base of ventral. Caudal emarginate, the inner rays 5 as long 
as the outer, which are equal to the length of head. Caudal peduncle 2} times as 
long as deep. Body crossed by 5 dark brown nearly vertical bands; fins, except 
the anal, each crossed by 2 similar bands ; anal with a dark spot. 
Total length 57 mm. 
One specimen: R. Amazon. 
15. ANCISTRUS BACT. 
Chetostomus bachi Bouleng. Trans. Zool. Soc. xiv. 1896, p. 425, pl. xli. fig. 1. 
Depth of body 43 times in the total length, length of head 22 times. Head 1,', 
times as long as broad and 1{ times as long as deep. Diameter of eye 6 times in the 
length of head, interorbital width 1} times, length of snout 14 times. Length of 
mandibular ramus 33 times in the interorbital width. Snout narrowed anteriorly ; 
supraorbital margins not raised ; supraoccipital without median ridge; temporal 
plates not carinate; interoperculum armed with 12-15 slender spines, the longest 
equal to 1; times the diameter of eye. Scutes margined with short spines, not 
carinate, 25 in a longitudinal series, 8 between dorsal and adipose fin, 12 between anal 
and caudal. Supraoccipital bordered posteriorly by a median scute and by one on 
each side. Lower surface of head and abdomen almost completely covered with small 
granular scales. D.I7, the first ray nearly as long as the head, the last half as long; 
length of base of dorsal a little more than its distance from the adipose fin. A. I 4. 
Pectoral spine extending to middle of ventral. Caudal very obliquely emarginate, 
almost truncate, the longest ray twice as long as the shortest. Caudal peduncle 
2% times as long as deep. Uniformly coloured (in spirit) except for 4 or 5 faint dark 
vertical bands on the caudal. 
Total length 112 millim. 
One specimen: River Jurua. 
16. ANCISTRUS SCHOMBURGEII. 
Chetostomus schomburgkii Ginth. Cat. Fish. v. p. 245 (1864). 
Hemiancistrus schomburgkii Eigenm. & Eigenm. Proce. Cal. Ac. (2) ii, 1889, p. 43; Kindle, Ann. 
Ac. N. York, viii. 1895, p. 254, 
Depth of body 8 times in the total length, length of head 3 times. ee nearly as 
al 
