262 INSECTA. 



metathorax, is united to the abdomen and confounded with it. M. 

 Kirby was the first, I think, who thus designated this segment; but 

 Nitzsch, on the other hand, seems to have first employed the 

 others(l). The limits of this work interdict any exposition of the 

 subgenera he has established. We will merely remark that the one 

 he calls Goniodes, the fourth subgenus of Philopterus, is exclusively 

 proper to the Gallinacese. In the collection of memoirs which ter- 

 minates our Histoire des Fourmis, we have minutely described a 

 species of Ricinus Philopterus, Nitzsch. 



M. Leon Dufour, with the P. meliteas of Kirby, previously well 

 observed by De Geer, who considered it as the larva of the Meloe 

 proscarcibasus, as well as by that celebrated entomologist, has formed 

 a new genus Triongulin des cindrenettes the characters of which 

 he has figured and published in the Ann. des Sc. Nat. XIII, 9, B. 

 If this Insect be not the larva of that Meloe, as in the opinion of M. 

 Kirby, there is no doubt but that it forms a peculiar subgenus in the 

 order of the Parasita; but according to the researches of MM. Le- 

 peletier and Servile, the idea of De Geer is confirmed. 



ORDER IV. 



SUCTORIA(2). 



The Suctoria, which constitute the last order of the Ap- 

 tera, have a mouth composed of three(3) pieces, enclosed 

 between two articulated laminse, which, when united, form a 

 cylindrical or conical proboscis or rostrum, the base of which 

 is covered by two scales. These characters exclusively dis- 

 tinguish this order from all others, and even from that of the 

 Hemiptera, to which, in these respects, it approximates the 

 most closely, and in which these Insects were placed by Fabri- 

 cius. The Suctoria, besides, undergo true metamorphoses, 

 analogous to those of several Diptera, such as the Tipulse. 



(1 ) See our general observations on the class of Insects. 



(2) Siphonapterdi Lat. 



(3) Rcesel represents but two; Kirby and Straus, how ever, have observed, one 

 more. According to the latter, the two scales which cover the base of the ros- 

 trum are palpi. 



