268 ME. 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. 

 Bio Jacuhy, Rio Grande do Sul. 



5. Otocinclus maculicauda. 



Otocinclus maculicauda Steind. Sitzb. Ak. Wien, ixxvi. pt. 1, 1877, p. 222, pi. i. fig. 2. 

 Parotocinclus maculicauda Eigenm. & Eigenm. Proc. Cal. Ac. (2) ii. 1889, p. 41, and Occ. Pap. 

 Cal. Ac. i. 1890, p. 392. 



Depth of body about 6 times in the total length, length of head 3 times. Diameter 

 of eye 6^ times in the length of head, interorbital width 2f 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 

 lon<r 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. Otocinclus notatus. 



Hisonotus notatus Eigenm. & Eigenm. Proc. Cal. Ac. (2) ii. 1889, p. 40, and Occ. Pap. Cal. Ac. i. 

 1890, p. 391. 



Depth of body 6—6^ times in the total length, length of head about 3 times. 

 Diameter of eye 7-7-j 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. 



7. Otocinclus nigricauda. 



Otocinclus nigricauda Bouleng. Proc. Zool. Soc. 1891, p. 234, pi. xxv. fig. 3. 

 Hisonotus Icevior Cope, Proc. Am. Phil. Soc. xxxiii. 1894, p. 95, pi. vii. fig. 12. 

 Hisonotus leptochilus Cope, t. c. p. 96, pi. vii. fig. 11. 



