I HE SAW FLT. 
49 *- 
Genus II. — F’cnthredo. She Saw Fly, 
"J’he family of faw flies have two jaws, but no trunk or 
probofcis. Their fling, which is almofl hid by the ab- 
domen, is of a fingular ftrufture, being cornpofed of two 
plates, and dentated like a faw. The abdomen is clofely 
united to the thorax, without the intervention of a fmall 
jjalk, as in the former and fucceeding genera. 
From the fliape of the antennas, the tenthredines have 
been arranged into fix tribes, confiding of about thirty- 
nine different fpecies. The moft remarkable fa£t in their 
hiftory feems to be the application of her faw by the fe- 
male, in cutting out a fpace in the twigs or buds of trees 
to contain her eggs : The whole procefs is performed with 
great ingenuity ; and from the tamenefs ot thefe animals, 
may eafiiy be obferved. 
The eggs thus depofited have the peculiar property of 
increafing their fize every day, till the young worms are 
ready to burft from them. The worm ol the tenthredo 
lias often been taken for the filk worm ; an animal 
which it nearly refembles, except in the feet, which are 
more numerous : Like the filk worm, too, the young 
tenthredo conltructs a cod in which it may undergo its 
lafi: transformation.; and its edifice confifts of two coats 
ol filk, the external coarfe and ftrong, the interior of a 
finer fubftance *. 
The 
* Reaumur, Tom. V. Mem. iiii 
