188 NATURAL ARRANGEMENT OF INSECTS. 



the whole of them have but an obsolete neuration of the 

 wings. We have already referred to the remarkable 

 Thoracantha. Our space admits of no more than alluding 

 to the ProctotrupidcE, and the interesting genera they 

 include; and, among others, the ant- like form of Gona- 

 topuSj with its extraordinarily chelated anterior tarsi; 

 Inostemma, with its recurved abdominal spine ; and the 

 elegant little Mymar, with its pedunculated and beau- 

 tifully ciliated wings. 



(162.) We must spare a few words for the Chrysi- 

 dida, which present the only instance throughout the 

 Hymenoptera of a tubuliferous ovipositor: their bodies, 

 also, are formed in a singular manner, being more or 

 less fornicate ; and their abdominal segments are more 

 or less reduced in number, from what we observe else- 

 where ; and we are acquainted with an African species 

 in which only two are apparent. Parnopes, of which 

 we know three species, presents a sexual difference in the 

 number of these segments, the male having one more 

 than the female. It has also an elongated rostrum, like 

 Bembex, upon which it is parasitical. These insects 

 are all richly metallic, and they are all parasites; and 

 amongst them Cleptes appears to lead off to Meria in 

 the circle of the fossorial aculeates. 



(163.) The remainder of the Hymenoptera are all, 

 in their larva state, vegetable feeders. The Cynipsidce, 

 or gall flies, form a marked and distinct group, although 

 of but limited extent. Their young are reared within 

 the galls which the parent insect produces by the punc- 

 ture it makes upon the different parts of plants : the 

 juice it instils, and what is secreted by the larva, causes 

 the plant to throw out excrescences, which all differ ac- 

 cording to the species which excites them. We cannot 

 here go into their particulars. This group seems to 

 pass, by means of Oryssus, through the Siricidce, into 

 our last large group, the aberrant Tenthredines. The 

 preceding have all been internal feeders in their larva 

 state ; the Siricidce feeding within trees generally of the 

 fir tribe. They are large and conspicuous insects, and 



