FISHES OF THE FAMILY LORICAEIID^E. 221 



Hemipsilichthts gobio. 



Xenomystus gobio Liitk. Vid. Medd. 1873, no. 13, p. 217, pi. iv. 



Hemipsilichthys gobio Eigenm. & Eigenm. Proc. Cal. Ac. (2) ii. 1889, p. 46; Occ. 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 of times. Head li times as long 

 as broad and lf^ times as long as deep. Diameter of eye 9 times in the length of head, 

 interorbital width 2^- times, length of snout 1^ times. Head without ridges or keels, 

 the supraorbital ridges not raised, the interorbital space and occipital region fiat, 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 -f the length of head, the last ^ as 

 long; length of base of dorsal 1|- 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 //. gobio as the male, and P. heylandii as the female, 

 of one and the same species. 



3. Ancisteus 1 . 



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 ; Gunth. Cat. Fish. v. p. 251 (1864) ; Eigenm. & Eigenm. Occ. 



Pap. Cal. Ac. i. 1890, p. 427. 

 Pseudancistrus Bleek. Ned. Tijd. Dierk. i. 1863, p. 77 ; Eigenm. & Eigenm. t. c. p. 434. 

 Hemiancistrus Bleek. t. c. p. 78 ; Eigenm. & Eigenm. t. c. p. 417. 

 Parancistrus Bleek. t. c. p. 79; Eigenm. & Eigenm. 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. 503 & 504). 



