THE 
MUSCLE MONOCULUS. 
Generic Character. 
Feet formed for fvvimming. 
Body covered by a cruftaceous fhell. 
Eyes (in moft lpecies) approximated, fixed in the 
fliell. 
Specific Character, &c. 
Brown oval MONOCULUS, with downy fhell. 
Oval-flielled MONOCULUS. 
Mufcle MONOCULUS. 
The Monoculus Conchaceus, fo remarkable for 
its refemblance to a mufcle in miniature, may be 
difcovered in almoft every flagnant water during the 
fummcr months. In fize it varies according to age; 
being fometimes fcarce larger than a grain of fand, 
and fometimes nearly the tenth of an inch in length. 
Its color is a pale brown, with a flight calf of yellow. 
