FISHES OF THE FAMILY LORICARIIDA. 221 
HEMIPSILICHTHYS GOBIO. 
Xenomystus gobio Liitk. Vid. Medd. 1873, no. 13, p. 217, pl. iv. 
Hemipsilichthys gobio Kigenm. & Eigenm. Proc. Cal. Ac. (2) il. 1889, p. 46; Oce. Pap. Cal. Ac. 
i. 1890, p. 438. 
Plecostomus heylandii Bouleng. Ann. Mag. Nat. Hist. (7) v. 1900, p- 165. 
Depth of body 6 times in its length, length of head 33 times. Head 14 times as long 
as broad and 1 times as long as deep. Diameter of eye 9 times in the length of head, 
interorbital width 2} times, length of snout 14 times. Head without ridges or keels, 
the supraorbital ridges not raised, the interorbital space and occipital region flat, the 
sides evenly convex ; snout broad, rounded, with a naked margin ; operculum well- 
developed, interoperculum little movable, not spinate. In some specimens (males) the 
sides of the head tumid and armed with a few short spines. Scutes spinulose, not 
carinate, 27-29 in a longitudinal series, 5 between supraoccipital and dorsal, 9 between 
dorsal and adipose fin, 13 between anal and caudal. Lower surface naked, the naked 
area extending over the lower scutes to behind the anal fin. Males with a moderately 
elongate anal papilla. D. I 7, the first ray equal to 3 the length of head, the last } as 
long; length of base of dorsal 13 times in its distance from the adipose fin. A. I 5. 
Pectoral spine short, barely reaching the base of ventral ; ventrals as long as pectorals ; 
pectoral and ventral spines stout, thickly covered with short spinules, which are 
stronger in males. Caudal vertically truncate or weakly emarginate. Caudal peduncle 
3 times as long as deep. Olivaceous; fins with dark spots or markings. 
Total length 150 mm. 
One specimen: R. Parahyba and Santos, S.E. Brazil. 
On comparison of Liitken’s description and figure with the unique specimen preserved 
in the British Museum, I regard H. gobio as the male, and P. heylandii as the female, 
of one and the same species. 
3. ANCISTRUS !. 
Hypostomus (part.) Cuv. & Val. Hist. Nat. Poiss. xv. p. 489 (1840). 
Ancistrus (part.) Kner, Denkschr. Ak. Wien, vii. 1854, p. 256. 
Ancistrus Gill, Ann. Lye. N. York, vi. 1858, p. 407. 
—Pterygoplichthys Gill, t. c. p. 408; Giinth. Cat. Fish. v. p. 251 (1864) ; Eigenm. & Eigenm. Oce. 
Pap. Cal. Ac. i. 1890, p. 427. 
Pseudancistrus Bleek. Ned. Tijd. Dierk. i. 1863, p. 77 ; Eigenm. & Eigenm. t. ec. p. 434. 
Hemiancistrus Bleek. t.c. p. 78; Eigenm. & Eigenm. t. ec. p. 417. 
Parancistrus Bleek. t. c. p. 79; Eigenm. & Vigenm. t. c. p. 422. 

1 Eigenmann and Kennedy describe two new species of this genus under the names Pterygoplichthys anisiti 
and P, juvens, too late for incorporation in this paper (Proc. Ac. Philad. 1903, pp. 508 & 504). 
