SOUTH AMERICAN NEMATOGNATHI. 433 



Head 3; D. I, 11-13; A. 5; Lat. 1. 28. 



Over fifty specimens .13-, 47 m. Santarem; Cudajas; 

 Rio Negro; Teffe; Jutahy; Villa Bella; Obidos; Tabatinga; 

 Bahia (very dark). 



403- Pterygoplichthys jeanesianus. 



Liposarcus jeanesianus Coiie, Proc. Acad. Nat. Sci. Phil. 1874, 135 

 (Nauta); id. Proc. Am. Philos. Soc. xvii, 1878, 681 (Naiata). 



Pterygoplichthys jeanesianus Eigenm. & Eigenm. Proc. Cal. Acad. 

 2d Ser. ii, 45, 1889. 



Habitat: Nauta. 



This species is very closely related to P. pardalis from 

 which it differs in the size of the eye. 



404. Pterygoplichthys multiradiatus. 



Hypostomus multiradiatus Haucock, Zool. Joiirn. iv, 246, 1828 



(Demarara). 

 Liposarcus multiradiatus Gtinther, v, 238 (Demarara). 

 Habitat: Demarara. 



This species is known from a single small specimen. 



405. Pterygoplichthys lituratus. 



Ancistrns lituratus Kner, Hypostomiden, 285, pi. v, fig. 3, 1863 



(Kio Guapore). 

 Pterygoplichthys lituratus Gitnther, v, 252, 1864 (copied); Eigeum. 



Sl Eigenm. 1. c. (Eio Preto; Eio Piity; Sao Gougalo; Xingn 



Cascade). 

 Chcetostomus lituratus Steiudachner, Flussf. Siidam. ii, 15, 1881 (Kio 



Guapore; Kio Puty; Santarem). 

 Habitat: Eastern Brazil; Rio Guapore; Amazon. 



Broad, elongate, the depth IJ in the width. Head 

 broad; occipital with a long blunt keel; snout pointed, 

 entirely granular in the adult, temporal keel strong; in- 

 teropercle larger, more freely erectile and more copiously 

 provided with recurved spines or bristles than any other 

 species. 



Orbit 2f-4| in the snout, 5|-8| in the head, 2i-4 in 

 the interorbital. Superciliary margin and edge of nares 

 greatly raised in the young; interorbital convex in the 

 adult. 



Lateral scutes strongly keeled. 

 28 



