Notes on some South American Fishes. 638 



Pimelodus (Pseudorhamdia) nigriharhis Bonlenger, Ann. and Mag. Nat. Hist. 

 (6), IV, 1889, 266 (Catnapuam) ; Proceedings Zool. Soc. Lond., 1^91, 

 232, pi. XXV, fig. 1 (Carnapuam). 



I have before me three specimens 165 — 172 mm. long, which are 

 certainly the excellently described and figured P. nigriharhis Bou- 

 lenger. The length of the barbels varies considerably. These 

 specimens are just as certainly identical with the P. valenciennis 

 Liitken. In justice to Dr. Boulenger I may state that the fault lies 

 in the transcription of the original description into our ''Revision 

 of the Nematognathi." The width of the head is given as " 2^ in 

 its length," and ''eye 6 in length of head." The authors of the 

 "Revision" neglected to state that in this particular species the 

 length of the head was measured "til Enden af Nakkendvaexten." 

 Measured in this way the specimens before me have the following 

 proportions: width of head 2 J (If — 2 to end of opercle) ; eye 6 in 

 length of head (4-J — 5). The type was about 240 mm. long, and 

 in the Latin diagnosis Liitken does not mention what he means by 

 the length of the head, but in the Norwegian text (Vidensk. Med., 

 1874, 201), he defines the length of the head as above. 



Pimelodus Clarias (Bloch). Three specimens of form macidatus. 

 PlecostoniUS cominersoni (Valenciennes). Four small specimens. 

 lUicrolepidogaster nigricailda (Boulenger). A large number of 

 specimens. 



In many the belly is naked, but usually it is covered with small 

 irregular granular plates. In the related genus Otocinclus the belly 

 is always covered with two or three series of large plates. In the 

 position of its ventrals this species agrees with Otocinclus. 



Alicistrus cirrllOSUS (Val.). Many specimens. 



LiOricaria lima Kner. Seven specimens. 



Callichthys callichthys (Liunseus). Two specimens ; a specimen 



about 30 mm. long, has no trace as yet of the lateral plates. 

 Corydoras paleatllS (Jenyns). Nine specimens. 

 Macrodon malabaricus (Bloch). Four specimens, Rio Grande do 



Sul. 

 CurimatUS gilberti Qnoy & Graim. One specimen. Rio Grande do Sul. 

 TetragonopterMS riltilllS Jenyns. Many specimens. Rio Grande do 



Sul. Anal 8, 26—28 ; Lat. 1. 40—42. 



Tetragonopterus maculatus lacustris Liitken. 



