148 MANDIBULATA. TRICHOPTERA. 



From these tables it is manifest that considerable diversity occurs 

 amongst the insects of this order, not only in the larva, but in the 

 imago states. Pictet regards the above groups as genera only, but 

 I think the generality of them bear a higher designation, and may 

 probably be nearly equivalent to families ; as such, in the present 

 state of our knowledge of the Trichoptera, I shall consider them; 

 and I have endeavoured to characterize them by a slight modification 

 of the above tables, whereby I have reduced tlie anomaly resulting 

 from taking characters peculiar to the sexes, as employed by Pictet, 

 in some of his groups : — 



Pfrfes baud calcaribus instructis ; . . . .1. AcENTROPiDiT:. 



calcaribus instructis ; 

 ^rtten?i« filiformes, aut pectinatse : . . .2, Hydroptilid^?:. 



setaceas ; 

 AltB posHcce hand pVicati : . . . .6. PsychomiDj?;. 



plicati ; 

 anticcB nervis transversalibus ; 



Palpi maxillccres, mediocres, subhirsuti : . 8. Phryganid.e. 



elongati, hirsutissimi : . 7- Leptocerid^. 



anticcB nervis transversalibus fere destitutis ; 

 Palpi maxillares 



articulo ultimo elongate, filiformi : . . .4. Hydropsychid^. 



brevi, ovato; arti°. 2-do elongate : . 5. SERicosxoMiDiE. 



brevissimo : . 3. Rhyacophilid^. 



Family I.— ACENTROPID.E mihi. 



Antehnos nearly setaceous, remote, short : maxillary palpi drooping, 3-jointed, 

 labial wanting: head and thorax clothed with scale-like hairs, the latter 

 furnished on its sides with a pair of petagice, or tippets : tvings deflexed, 

 anterior acute, posterior ovate, furnished with a connecting bristle at the 

 base : abdomen rather elongate : legs moderate ; femora and tibiw shortish, 

 of nearly equal length, the latter not furnished with spurs : tarsi 5-jointed. 



nomenclature of the species has been greatly embarrassed, many of Pictet's 

 insects being synonymous with the indigenous ones, and thus in repeated 

 instances a third name has been imposed on the same species ; and an additional 

 inconvenience arises from the names of Mr, Curtis's insects occurring in a 

 miscellaneous work, as before referred to, while those of Pictet appear in a 

 work expressly devoted to the subject, and will consequently be more generally 

 employed, although not strictly having the priority. 



