PLATE II. 

 FIG. I. 



MONOCULUS QUADRICORNIS. 



Aptera. 



Apterous infe&s are diftinguifhed chiefly by having no wings in, 

 either male or female. 



Generic Character. 



The feet are formed for fwimming. The body is covered with a 

 cruftaceous cafe or fhell. The eyes fixed in the fhell very near each 

 other. 



Specific Character. 



Grey brown. One eye. Antennae four. Body diminiihes towards 

 the tail, which is long and bifid, with three or four ftrong hairs on 

 each fide. A bag of eggs on each fide of the tail. Length half a 

 line. — Berk. Out. 



Although this infe£t may have been noticed by many fwimming, or 

 rather darting fwiftly in various directions in water; its minutenefs is 

 fuch, that the moft attentive could never have comprehended precifely 

 its component parts ; but the microfcope difcovers it to be an animal 

 of fuch fmgular formation as highly to deferve the attention of the 

 naturalift. It is covered by a firm cruftaceous fubftance, divided into 

 annulations, and armed in feveral parts with fpines and briftles ; not- 



withftandino- 



