430 ON THE TRIBES 



We now look for Mandibulata which have cylindrical 

 larvae with membranaceous feet, and the genus Phryganea 

 appears to the view. 



Trtchoptera. 



That the Urocerata, with their hexapod larvae, form an 

 osculant order between these and the true Hymenoptera, 

 cannot be doubted; they may, in pursuance to the custom 

 of naming orders from some peculiarity of the wings, be 

 called Bomboptera, in allusion to the unusual noise which 

 they make in flying, and from which they borrow their 

 French name of Ichneumons-Bourdons. The important 

 question, however, is, Whether the genus Tenthredo of 

 Latreille, which is evidently further removed from the true 

 Hymenoptera than the genus Sirex, ought to be esteemed 

 osculant with it, or as constituting a ganglion of the same 

 order in which Phryganea is placed ? I confess that I am 

 rather inclined to adopt the latter alternative, however 

 contrary to the general opinion, and that for the following 

 reasons. 



The Perlariaoi the Genera Inseclorum, or M. Lamarck's 

 family of Phryganidg, is evidently a natural group formed 

 of those insects whose larva?, admirably described by Aris- 

 totle under the name of Xylopthori, are aquatic and live 

 m tubes or sheaths, which they have the instinct to make 

 for themselves. This group is lately divided by Latreille 

 into Perlides and Plicipennes, the last of which constitute 

 Mr. Kirby's order Trichoptera. Such a name, thus found- 

 ed on too trivial a character for an order, is perhaps ob- 

 jectionable not only as inapplicable to all Phryganea, but 

 because it places the genus Perla in another order, when 

 the larva, the metamorphosis, the antenna?, the mouth 



