Cockerell: Scales of Characinid Fishes. 107 



nuinlier alioiit three to six on each side. Thus the longitudinal lines 

 in M. cotinho. etc., are wholly homologous with the transverse lines 

 in M. grandisquamis. M. grandisqnamis and dichrourns surely 

 should be separated, at least subgenerically, from the other species 

 examined. 



Tetragonopterus Cuvier. 



Tctragonopterus chalceiis x'\gassiz (Plate XXVII, fig. 4). Broad scales, 

 the outline well shown in the figure; breadth about four and one- 

 fourth mm. As in Bryconamericus, there is a strong line or band 

 across the middle of the scale, and the apical (exposed) field is 

 without any distinct sculpture. The much finer circuli, however, do 

 not stop at the line, but go a short distance above it, especially at 

 the sides. The base of the scale is wavy. The transverse line 

 belongs of course to the radial system, but otherwise there arc no 

 radii. The lateral circuli are directed very obliquely toward the 

 margin. 



Reviewing the Tetragonopterine scales, it must be said that Cteno- 

 brycon stands quite apart. Tetragonopterus and Bryconamericus may 

 be grouped together, though not very closely related; Creatochanes, 

 still more dilTerent, may yet be placed in the same vicinity. Astyanax 

 bimaculatus "may be a stem-form leading toward the more usual 

 Astyanax type, which connects with the Henvigrammus series, but the 

 latter could not properly include such a form as A. bimaculatus. 

 Hemigrammus, Hyphessobrycon, Pristella, Phenacogaster, Deuterodon, 

 part of Astyanax, and Moenkhausia may be grouped together. In all 

 about four distinct tribes are apparently indicated, or perhaps the 

 subfamilv should be divided. 



Unknown to me. 



Not examined. 



DlAPOMIN^. 



Stevardiin.e. 



PlABUCININ.E. 



Chalceus macrolepidotus Cuvier. A fish having the most amazing 

 resemblance to Alestes macrolepidotus (Cuvier & Valenciennes) of 

 the River Nile, though on closer inspection important difTerences 

 are apparent in the structure of the head. The resemblance extends 

 even to the general light straw-color, and the iridescent lilac borders 



