62 Mr. C. T. Regan on the South- American 



Biofo(Jo)na tceniatum, Pellegr. Mom. Soc. Zool, France, xvi. 1903, p. 187 

 (1904). 



Depth of body 2| in the leiifj^th, length of head 3. Snout 

 much shorter than eye, tlie diameter of which is 2| in the 

 length of liead, interorbital width 31 . Depth of praeorbital 

 ? the diameter of eye. Maxillary extending to below ante- 

 rior i^^ of eye ; jaws equal anteriorly; fold of the lower lip 

 continuous ; cheek with 3 series of scales ; no scales on the 

 prseo])erculuni ; 3 or 4 very small gill-rakers on the lower 

 part of anterior arch. Scales 23 ^ ; upper latei'al line ex- 

 tending to below posterior part of spinous dorsal, from which 

 it is separated by only 1 or ^ a scale for most of its course. 

 Dorsal XV (XVI) 6 (7), the spines increasing in length to 

 the last, which is more than | the length of head. Anal 

 III Q, the third spine slightly more than -^ the length of 

 head. Pectoral a little longer than the head. Caudal 

 rounded. Caudal peduncle 4^ as long as deep. A blackish 

 longitudinal band from eye to base of caudal ; an oblique 

 blackish stripe from eye to iuteropcrculum ; a dark stripe 

 from eye to mouth ; membrane between the first 3 dorsal 

 spines blackish; a blackish spot at the base of caudal ; soft 

 vertical fins more or less distinctly spotted. 



R. Amazon ; Guiana. 



1. (60 mm.) type of the species. R. Cupai. H. W. Bates, Esq. 



2. Heterogramma Agassizii. 



Genphaf)us (Mesoj)s) Ayassizii, Steiud. Sitzb. Ak. Wien, Ixxi. 1875, 



p. Ill, pi. viii. fig. 2. 

 Biotodoma Aqusaizii, Pellegr. Mem. Soc. Zool. France, xvi. 1903, 



p. 187 (1904). 



Depth of body 2^-3 in the length, length of head 2f-3. 

 Snout a little shorter than the eye, the diameter of Avhich is 

 3 in the length of head and equal to the interorbital width. 

 Depth of pra^orbital a httle more than \ the diameter of eye. 

 Maxillary extending a little beyond the vertical from anterior 

 margin of eye ; jaws equal anteriorly; fold of the lower lip 

 continuous ; cheek with 3 series of scales ; no scales on the 

 prseoperculum ; 4 very small gil!-rakers on the lower part of 

 anterior arch. Scales 23 ^^ ; upper lateral line extending 

 to below posterior part of spinous dorsal, from which it is 

 separated by only }, a series of scales for most of its course. 

 Dorsal XV-XVI 7 , the spines only slightly increasing in 

 length after the fifth, the last \~t the length of head. 

 Anal III 6^ the third sj)ine as long as the last of the dorsal. 



