natural sciences of philadelphia. 291 



Chromidid^, 

 Erythinid^, 

 Characinid^, 



SiLURIDuE, 



The general character of this list is that of any other part of 

 the Amazon basin, presenting peculiarities in peculiar species and 

 in genera not found in the lower Amazon. Such genera amonor 

 Characindae are TrijMrtheus^ Megalobrycon, Aphyocharax, Iguano- 

 dectes^ and Stethaprion ; among Siluridse, Diariema, Brochis, Za- 

 tliorax, Pliysopyxis^ Otocinclus, and Pariolius. A genus (Cha- 

 racidium) previously only known by one small species from a 

 Brazilian coast stream, has its range greatl}"^ extended by the 

 discovery of a species in the Ambyiacu. 



The species contained in the Perkins collection are as follows : — 



CHROMIDIDJE. 



Pterophyllum scalare, C. y. 



Symphysodon DISCUS, Heck. 



CiCHLA ocellaris, B1. Schn. 



Geophagus proximus, Cast. Radii D. XYII-XTIII-11 ; A. III- 



8. Scales 6-34-12, upper and lower halves caudal fin scaly to 



near end. 

 Hygrogonus ocellatus, Agass. 



SCIAENID.!:. 



One species. 



PLEUKONECTIDa;. 



One species. 



OSTEOGLOSSID.E. 



OSTEOGLOSSUM BICIRRHOSUM, Vand. 



CHARACINID.S:. 

 CURIMATUS CYPRINOIDES, L. 



Hemiodus microlepis, Kner. 

 Tetragonopterus chalceus, Artedi. 

 Myletes albiscopijs. Cope. 

 Myletes bidens, Spix. 

 Myletes, sp. nov. 

 1872.] 



