CLASS VI. ORDERS II. TO V* $5 



ORDERS SECOND TO FIFTH. 



Head distinct from the trunk. 



Remark. These four orders of Latreille must 

 be united, if we retain the old Linnean genera, as 

 adopted by Shaw, according to the plan of this 

 text-book. 



SQUILLA, tail longer than the thorax ; each man- 

 dible bears a feeler ; eyes pedicelled and movea- 

 ble. 



ONISCUS, (sow-bug,) legs fourteen ; antennae 

 setaceous ; body oval. 



MONNOCULUS, (swimming-bug,) feet formed for 

 swimming ; body covered by a crustaceous tegu- 

 ment ; eyes, in most species, approximated and 

 Imbedded in the shell. 



