FISHES OF THE FAMILY LORICARIIDA. 261 
caudal. Pectoral spine extending to base of ventral. Caudal truncate or slightly 
emarginate, the outer rays produced. Caudal peduncle 14-2 times as long as deep, 
Numerous round blackish spots on head, body, and fins. 
Total length 320 mm. 
‘Two specimens (including the type of the species): R. Amazon; Marajo Island. 
5. PSEUDACANTHICUS FORDII. 
Chetostomus fordii Giinth. Proc. Zool. Soc. 1868, p. 231, pl. xxi. 
Hemiancistrus fordii Kigenm. & Eigenm. Proc. Cal. Ac. (2) ii. 1889, p. 43. 
9 
Depth of body 53-53 times in the total length, length of head 3 times. Breadth 
of head 1§ times in its length, diameter of eye 8 times, interorbital width 
34-33 times, length of snout 13 times. Lower jaw with 6-8 teeth on each side. 
D. I 8; length of base of dorsal equal to its distance from the caudal. A. I 5, 
extending, when laid back, 3—? of the distance from its base to the caudal. Pectoral 
spine extending to base of ventral. Caudal slightly emarginate, the outer rays 
produced. Caudal peduncle 2-2} times as long as deep. Brown, with small white 
spots on body and fins. 
Total length 180 mm. 
Four specimens: Surinam. 
4, {PSEUDACANTHICUS HYSTRIX. 
Rinelepis hystrix Cuv. & Val. Hist. Nat. Poiss. xv. p. 486 (1840). 
Chetostomus hystrix Capello, Jorn. Sci. Lisboa, ii. 1870, p. 64, pl. vil. 
Hemiancistrus hystrix Figenm. & Higenm. Proc. Cal. Ac. (2) 1. 1889, p. 43. 
This species is apparently closely allied to P. fordii, but the differences seem too 
great to be due to changes during growth in the same species. The only specimen 
known, from the Rio Negro, is 760 mm, in total length, and has been described and 
figured by Capello. ‘The most noticeable features are the small eye (diameter 15 times 
in the length of head), the long pectoral spine, extending to the extremity of the 
ventral, and the length of the base of the dorsal considerably less than its distance 
from the adipose fin. 
8, ACANTHICUS. 
Acanthicus Spix, Gen. et Spec. Pisce. Bras. p. 2 (1829); Giinth. Cat. Fish. y. p. 253 (1840); 
Eigenm. & Eigenm. Proc. Cal. Ac. (2) 11. 1889, p. 46, and Occ. Papers Cal. Ac. i. 1890, 
p. 440. 
Rinelepis (part.) Cuv. & Val. Hist. Nat. Poiss. xv. p. 479 (1840). 
This genus differs from Ancistrus in the great development of the temporal plates, 
which extend back far beyond the clavicles, so that the first two or three scutes of the 
