268 MR. C. TATE REGAN ON THE 
the length of head; 25 scutes in a longitudinal series. Light brown, with a series of 
4-6 dark spots along the middle of the side, and a similar series above them. Fins 
with dark spots or bars. Recorded up to 56 mm. in total length. 
Rio Jacuhy, Rio Grande do Sul. 
5, OTociNcLUS MACULICAUDA. 
Otocinclus maculicauda Steind. Sitzb. Ak. Wien, Ixxvi. pt. 1, 1877, p. 222, pl. i. fig. 2. 
Parotocinclus maculicauda Eigenm. & Figenm. Proc. Cal. Ac. (2) ii. 1889, p. 41, and Oce. Pap. 
Cal. Ac. i. 1890, p. 392. 
Depth of body about 6 times in the total length, length of head 5 times. Diameter 
of eye 64 times in the length of head, interorbital width 2} times, length of snout 
twice. Occipital region evenly convex, without crests. Scutes spinulose, not carinate, 
25 in a longitudinal series ; lower surface of head with a naked area in front of the 
clavicles ; abdomen covered with 3 series of plates. D. I 7, origin of dorsal a little 
behind that of ventrals. Adipose fin well developed. A. I 5. Pectoral spine 
extending to middle of ventral. Caudal emarginate. Caudal peduncle 3 times as 
long as deep. Olivaceous; caudal with a large blackish blotch on its basal half and a 
small blackish spot at the tip of its lower lobe. 
Total length 37 mm. 
A single specimen from Santa Cruz, South-eastern Brazil. 
6. OrocINCLUS NOTATUS. 
Hisonotus notatus Eigenm. & Eigenm. Proc. Cal. Ac. (2) 11. 1889, p. 40, and Occ. Pap. Cal. Ac. 1. 
1890, p. 391. 
Depth of body 6-6} times in the total length, length of head about 3 times. 
Diameter of eye 7-74 times in the length of head, interorbital width 2} times, length 
of snout twice. Occipital region evenly convex, without crests. Scutes spinulose, 
not carinate, 25 in a longitudinal series ; lower surface of head with a naked area in 
front of the clavicles; abdomen covered with 3 series of plates. D.I 7, origin of 
dorsal a little behind that of ventrals. No adipose fin. A. I 5. Pectoral spine 
extending nearly to middle of ventral. Caudal emarginate. Caudal peduncle 3 times 
as long as deep. Olivaceous; caudal with a large median blackish blotch which 
extends to the margin of the middle rays. 
‘Total length 40 mm. 
Four specimens from Santa Cruz, South-eastern Brazil. 
T. OTOCINCLUS NIGRICAUDA. 
Otocinelus nigricauda Bouleng. Proc. Zool. Soc. 1891, p. 234, pl. xxv. fig. 3. 
Hisonotus levior Cope, Proc. Am. Phil. Soc. xxxiil. 1894, p. 95, pl. vil. fig. 12. 
Hisonotus leptuchilus Cope, t. c. p. 96, pl. vil. fig. 11. 
