FISHES OF THE FAMILY LORICARIID#, 241 
29. ANCISTRUS GUENTHERI, sp. n. (Plate XII. fig. 3.) 
Plecostomus guttatus (non Cuy. & Val.) Giinth. Cat. Fish. v. p. 237 (1864). 
Depth of body 6 times in the total length, length of head 3} times. Depth of head 
twice in its length, diameter of eye 8 times, interorbital width 34 times, length of 
snout 1} times. Length of mandibular ramus 11 times in the interorbital width. 
Head, in other respects, similar to that of A. barbatus, except that the snout has a 
broad naked area at its tip. Scutes as in A. barbatus. Lower surface of head and 
abdomen entirely naked. D. I 7, the first ray equal to 3 the length of head, the last 
3 as long; Jength of base of dorsal nearly equal to its distance from the adipose fin. 
A. I 4. Pectoral spine not quite reaching the base of ventral. Caudal obliquely 
truncate. Caudal peduncle 2} times as long as deep. Colour uniform (in spirit). 
Total length 120 mm. 
One specimen : British Guiana. 
30. PANCISTRUS ANGULICAUDA. 
Plecostomus angulicauda Steind. Sitzb. Ak. Wien, lxxiv. 1876, p. 672, pl. xii. 
Delturus angulicauda, Kigenm. & Eigenm. Proce. Cal. Ac. (2) ii. 1889, p. 45, and Occ. Pap. Cal. 
Ac. 1. 1890, p. 437. 
Closely allied to A. barbatus. Length of head about 33 times in the total length. 
Head a little broader than long. Diameter of eye about 53 times in the length of 
head, interorbital width about 52 times, length of snout 12 times. Head without 
keels or ridges. Sides of the head with short bristles in the male, without bristles in 
the female. Scutes spinulose, not carinate, 24 in a longitudinal series, 7 between 
dorsal and adipose fin, 10 between anal and caudal. Supraoccipital bordered posteriorly 
by a pair of scutes. A keel in front of the spine of the adipose fin, formed by 3 or 4 
scutes. Lower surface of head and abdomen naked. JD. I 9, the first ray longer than 
the head, the last $ as long and connected by a membrane to the two scutes succeeding 
it. A. I 5. Pectoral spine extending beyond base of ventral. Caudal truncate. 
Caudal peduncle about 24 times as long as deep. Light brown, without spots. 
Specimens have been recorded up to 270 mm. 
South-eastern Brazil. 
31, fANCISTRUS PARAHYBE. 
Delturus parahybe Eigenm. & Eigenm. Proc. Cal. Ac. (2) ii. 1889, p. 45, and Oce. Pap. Cal. Ac. 
i. 1890, p. 438. 
Differs from the preceding species in having I 10 dorsal rays, 25-27 
longitudinal series, and all the fins with large round blackish spots. 
Rio Parahyba. 
scutes ina 
