CLASS V. 



INSECTS. 



THIS very numerous and various clafs confifts of fmall animals, 

 breathing through lateral fpiracles, armed t>n all fides with. a 

 bony fkin, or covered -with hair ; furnifhed with many htt y and 

 moveable antennas or horns, which j>roje£t from .the head, and are the 

 probable instruments of fenfation. 



They are deftitute of external nofirils and ears y though fome of 

 them evidently enjoy the fenfes of hearing and fmell. 



The eyes are ufually 2, fometimes more, without eyelids, and rarely 

 placed on a moveable peduncle. 



The 2 antenna are placed on the head, ufually before the eyes, are 

 compofed of an indefinite number of articulations, and convey an un- 

 known fenfation, probably that of the touch. 



The feelers are fenforial, moveable, affixed to the mouth, generally 

 4, fometimes 2 or 6, and confift of 2, 4 or 3 joints. 



The mouth is generally placed beneath the head, fometimes in the 

 bread, and in a few is wanting : the jaws are tranfverfe and move- 

 able laterally. 



The Jiemmata are 3 mining convex fpots placed on the crown. 

 The trunk is placed between the head and abdomen,, fupported by 

 the feet, with the thorax above, behind which is the fcutel or efcuteheon, 

 and the Jlernum and breaft beneath. 



The ahdomen is ufually annulate with 5 fegments, perforated at the 

 fides with 5 fpiracles or breathing holes, with the back above, the' 

 belly beneath, and is terminated by the tail, which is fometimes 

 armed with a fting. 



The wings are 2 or 4, the upper ones are often cruftaceouS ihells, 

 covering the lower ; fometimes femicruftaceous wing cafes, or of a 

 fubftance between the membranaceous wings and cruftaceous fliells. 



The legs confift of 3 diftincl divifions, the thighs, (hanks, and tarfi 

 which are articulate and terminated by nails ; fome have a handy or 

 chelate kind of claw with a moveable thumb. 



The poifers are compofed of a head affixed to a fmall pedicle, and 

 placed under the wings of the dipterous order, or fuch as have only 

 2 wings. 



A ^ The 



