FISHES OF THE FAMILY LORICARIID^E. 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. I 7, the 

 first ray a little shorter than the head, the last ^ 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 f 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. Ancistkus baciii. 



Chtetostomus bachi Bouleng. Trans. Zool. Soc. xiv. 1896, p. 425, pi. xli. fig. I. 



Depth of body 4^- times in the total length, length of head 2f times. Head 1-^- 

 times as long as broad and If times as long as deep. Diameter of eye 6 times in the 

 length of head, interorbital width If times, length of snout If times. Length of 

 mandibular ramus of 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. LoAver surface of head and abdomen almost completely covered with small 

 granular scales. D. I 7, 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 millitn. 



One specimen: Eiver Jurua. 



16. ANCISTEUS SCHOMBURGKir. 



Chmtostomus schomhurgkii Giinth. Cat. Fish. v. p. 245 (1864). 



Hemiancistrus schomhurgkii Eigenm. & Eigenm. Proc. 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. Head nearly as 



2 i 2 



