216 ZOOLOGY. 



venomous, but is used to pierce holes in substances proper 

 for the nourishment of the young, when they have pierced 

 the holes, they immediately deposit an egg therein. They 

 all possess four membranaceous wings. 



1. Cynips. Gall-Fly. Mo«<A with jaws ; antennce moni- 

 liform; sting or pzercer spiral, in some species con- 

 cealed in the body. 



The excrescences so common on maiiy vegetables, and 

 known by the name of galls^ are produced by the puncture 

 of these insects ; the larvae is soft, cylindrical, without feet ; 

 and inhabits the galls, feeding on juices of the tree ; the 

 pupa resembles the perfect fly, except in having only the ru» 

 diments of wings. 



i. Tenthredo. Saav-Fly. Mouth with jaws ; wings tumid, 

 flat ; sting composed of two serrated laminje, which are 

 tiearly secreted. 



The larvae of some of the species in this numerous genus, 

 bears a strong resemblance to some of the caterpillars of the 

 Lipedopterous Insects : but are distinguishable by the num- 

 ber of the feet, which are never fewer than sixteen, exclu- 

 sive of the thoralc pairs ; the larvae feed on the leaves of 

 plants, and the pupa is enclosed in a strong gummy case, 

 retiring in the autumn, and the perfect fly emerges 

 early in the ensuing spring. The serrated sting is used by the 

 female in the manner of a saw, to make incisions in the 

 twigs or stems of plants, where it deposits its eggs. 



