ANNULOSA: INSECTA. 357 



few nervttres ; sometimes absent. Mouth always provided with 

 biting-jaws or mandibles ; the maxillcz and labium generally con- 

 verted into a suctorial organ. Females having the extremity of 



Fig. 190. Goat-moth (Cossus ligniperda) and Caterpillar. 



the abdomen furnished with an ovipositor (terebra oraculeus}, con- 

 sisting generally of Jive or six pieces, of which the two outer form 

 a protective sheath. Besides the compound eyes, there are 

 usually three ocelli placed on the top of the head. The an- 

 tennae are generally filiform or setaceous. The metamorphosis 

 is complete, but the various parts of the pupa are visible through 

 the delicate enclosing membrane. The larvae are sometimes 

 provided with feet, and live on vegetable food (as in the Ten- 

 thredinidcz, fig. 191); but they are mostly footless, without a 

 distinct head, and fed by the adult. 



The Hymenoptera form a very extensive order, comprising 

 the Bees, Wasps, Ants, Ichneumons, Saw-flies, &c. The ovi- 

 positor, which is characteristic of the females of this order, is 

 very commonly modified so as to constitute a saw (serra), a 

 boring organ (terebra), or a sting (aculeus]. 



As regards the principal groups of the Hymenoptera, the 

 Saw-flies (Tenthredinidcs and Siricidce) form a very natural sec- 



