228 ME. C. TATE EEGAN ON THE 



Depth of body about i\ times in the total length, length of head 3 times. Head 

 slightly longer than broad and If- times as long as deep. Diameter of eye 7-i- times in 

 the length of head, interorbital width 2^- times, length of snout If times. Length of 

 mandibular ramus of times in the interorbital width. Snout narrowed anteriorly ; 

 supraoccipital with a strongly elevated median ridge ; supraorbital edges scarcely 

 raised; temporal plates carinate ; interoperculum armed with 12-15 spines, the 

 longest 1\ times the diameter of eye. Scutes mostly carinate, 28-29 in a longitudinal 

 series, 6-7 between dorsal and adipose fin, 1-3 between anal and caudal. Supraoccipital 

 bordered posteriorly by a median scute and one on each side ; 3 series of scutes 

 between nuchal and posthumeral series. Lower surface of head and abdomen 

 completely covered with small granular scales. D. I 12-13 ; length of base of dorsal 

 about If times its distance from the caudal. A. I 4. Pectoral spine extending to 

 anterior \ of ventral ; caudal emarginate. Caudal peduncle 2| times as long as deep. 

 Dark, with light spots or veimiculations on head, body, and fins. 



Total length 190 mm. 



One specimen : E,. Amazon ; Eastern Brazil. 



6. Ancistrus multikadiatus. 



Bypostomus muUiradiatus Hancock, Zool. Journ. iv. 1828, p. 246. 



Hypostomus partialis Casteln. Anim. Am. Sud, p. 42, pi. xx. fig. 3 (1855). 



Lij/osarcus muUiradiatus Giinth. Cat. Fis'h. v. p. 238 (18G4). 



Liposarcus partialis Giinth. t. c. p. 239. 



Liposarcus varius Cope, Proc. Ac. Philad. 1871, p. 284. 



Liposarcus jeanesianus Cope, ib. 1874, p. 135. 



Plecostomus partialis Peters, Monatsb. Ak. Berl. 1877, p. 471 ; Steind. Denksclir. Ale. Wien, xliii. 



1881, p. 112; ib. xlvi. 1882, p. G. 

 Pterygoplichthys partialis Eigenm. & Eigenm. Proc. Cal. Ac. (2) ii. 1889, p. 45; Occ. Pap. Cal. 



Ac. i. 1890, p. 431. 

 Pterygoplichthys jeanesianus Eigenm. & Eigenm. 1. c. et t. c. p. 433. 

 Pterygoplichthys muUiradiatus Eigenm. & Eigenm. Occ. Pap. Cal. Ac. i. 1890, p. 433. 



Depth of body 4-f-5^ times in the total length, length of head 3-3f times. Head 

 1^ times as long as broad and If- ]§ times as long as deep. Diameter of eye 6-^-9 

 times in the length of head, interorbital width 2-2^ times, length of snout twice. 

 Length of mandibular ramus 31-4 times in the interorbital width. Snout somewhat 

 narrowed anteriorly, entirely granular; supraoccipital with low median ridge; supra- 

 orbital edges not or very slightly raised ; temporal plates usually carinate ; inter- 

 operculum not notably spinate. Scutes spinulose, mostly carinate, 28-30 in a 

 longitudinal series, 6 between dorsal and adipose fin, 11-13 between anal and caudal. 

 Occipital bordered posteriorly by a median scute and by 1 or 2 scutes on each side ; 

 3 or 4 series of scutes between the nuchal and posthumeral series. Lower surface, in 

 the adult, completely covered with small granular scales. D. I 12-13, the first ray- 

 less than the length of head in the adult; length of base of dorsal 1^-1^ times its 



