CARPS. 205 



zoologist makes two distinct Families. We pre- 

 fer to consider them as Sub-families. 



1. PceciUana. In this group, the head is flat, 

 the jaws are broad, and flattened horizontally, 

 with a very small mouth, furnished with one or 

 more rows of very fine teeth ; the gill-openings 

 are large, with, in general, five gill-rays ; the 

 body is rather short, and clothed with large, 

 strong scales. This Sub-family comprises about 

 fifty species, which chiefly inhabit the rivers of 

 America. One little species is found in Sar- 

 dinia, and another {Cyprinodon umbra, Lacep.) 

 is remarkable as being one of the inhabitants of 

 those subterraneous lakes in Austria where per- 

 petual darkness reigns. 



Another species, still more interesting, as if to 

 make a superabundant use of the light which the 

 former is destined never to see, has the organ of 



HEAD OF FOUR- EYED LOACH. 



vision fourfold. It is the Anahleps tetrophthal- 

 miis, commonly known as the Four-eyed Loach of 

 the Brazilian rivers. This appellation is, how- 

 ever, only partially correct. " The eyes," ob- 

 serves Cuvier, "are prominent, placed under a 



