252 SILURID^. 



the base of the ventral. Yellowish, all parts with round blackish 

 spots. (Kner.) 



This species is known from a single example, 11^ inches long ; it 

 is from S. Vicente (Brazil). 



3. Pterygoplichthys gibbiceps. 



Ancistrus gibbiceps, Kner, Hypostvm. p. 284. taf. 5. fig. 2. 

 D. 1/13. A. 5. 



The length of the head is two-sevenths of the total (without 

 caudal) ; eye of moderate size, its diameter being two-sevenths of 

 the width of the interorbital space. Occiput with a large pear- 

 shaped prominence*. Interoperculum with about twenty very short 

 curved hooks. Scutes of the body keeled ; all the lower parts covered 

 with small shields. Barbels long, extending to the gill-opening. 

 Dorsal fin much longer than high. Five scutes between the two 

 dorsal fins. Pectoral spine as long as the head, scarcely extending 

 beyond the root of the ventral fin. Caudal obliquely truncated. All 

 parts with roundish black spots. (Kner.) 



Only a single specimen is known, 20^^ inches long ; from the Rio 

 Negro. 



4. Pterygoplichthys lituratus. 



Ancistrus lituratus, K/m; Ilypostum. p. 285. taf. 5. fig. 3. 

 D. 1/12. A. 5. 



The length of the head is one-third of the total (without cau- 

 dal) ; eye of moderate size, its diameter being one-fourth of the 

 width of the interorbital space in old indi\'iduals, whilst it is larger 

 in young ones. Occiput with a rather elevated ridge, which is not 

 broader behind than in the middle. Interoperculum with about 

 twenty short curved hooks. Scutes of the body keeled ; all the lower 

 parts covered with small shields. Barbels longish. Blackish, with 

 irregular, roimded, brownish-yellow spots ; fins with undulated 

 btreaks. (^Kner.) 



Eio Guaporc. 



97. RHINELEPISf. 

 Rhinelepis, Spix, Pise. Brasil. p. 4. 



One dorsal fin with eight rays ; anal fin short ; ventral six-rayed, 

 below the dorsal ; pectoral vnth a strong spine. Head and body 

 completely cuirassed, the former rather high, the latter rather short, 

 with four or five longitudinal series of large imbricate scutes on each 

 side ; tail not depressed. Snout produced, obtuse in front ; mouth 

 inferior, transverse, with a single series of very fine bent teeth in 

 both jaws ; palate toothless. Praioperculum immoveable ; inter- 

 operculum not armed. Gill-opening very narrow. 



BrazU. 



* Probably peculiar to old specimens. 



t 1. Einelcpis strigosa, C. ^ V. xv. p. 480. — Parana. 



