Tenthredo. H YMENOPTER A. 177 



maining ones are foft and membranaceous, but 

 deprived of the crotchets which terminate the 

 membranaceous feet of the others : befides this 

 diftinftion taken from the number of the feet, 

 their heads are formed very differently - 3 that of 

 the falfe caterpillar confiding of one hard fcale; 

 that of the true one, on the contrary, is com- 

 pofed of two pieces, or fcales, which Geoffroy 

 calls hoods ; the eyes of thefe laft are likewife 

 much larger than thofe of the others. 



Thelarv^oftheTenthredines feed chiefly upon 

 the rofe and willow trees, and undergo their laft 

 changement in the earth •, their fhrowd, or web, 

 refembles net-work, being compofed of large 

 filken threads, between each of which great 

 (paces are left, perhaps to let the humidity of the 

 earth pierce to the chryfalis ; the leaft excefs of 

 humidity ordrynefs in the earth kills thofe chry- 

 falids, for which reafcn it is very difficult to 

 bring them to perfection in-boxes : out of more 

 than three hundred larvas of Tenthredines, 

 which were nourifhed by Geoffroy, notmore than 

 five or fix fucceeded, though he took theutmolt 

 pains to keep the earth in a proper flate. Vid. 

 Geoff, Parts, t. 2, p. 269. 



The Tenthredo is called, by fome Englifli 

 Authors, the Saw-fly, from the formation of 



M its 



