TRICHOPTERA. 



147 



constructed on the model of those of the Lepidoptera, and their 

 general habit is towards those insects ; their mandibles likewise are 

 nearly obliterated, the collar is narrow and transverse, &c. But few 

 writers have attended to these insects, the admirable Treatise of 

 M. Pictet on the Phryganese of Switzerland being almost the only 

 guide towards their classification, &c., and from that work I have 

 extracted the two following tables,* showing the dissimilarities in the 

 larva,', and also some external characters of the imago : — 



Larvce with a case, opening with a round hole ; 

 segments of the thorax rounded ; 



external respiratory ort/aws isolated, legs moderately 



long: Phryganea. 



in tufts ; 



hinder legs long : Mystacide. 

 short : Sericostoma. 

 segments with the anterior angles pointed : . Trichostoma. 



with a case, opening by a cleft : . . . Hydroptila. 



without a case ; 



Pupa with a double envelope : . . Rhyacophila. 



single envelope : . . Hydropsyche. 



Imago. 

 Posterior wings folded ; 



with transverse nervures. 



Maxillary palpi moderate and slightly hairy : Phryganea. 

 long and hairy : . Mystacide. 



without transverse nervures. 



Maxillary palpi different in the sexes ; 



of the male clavate : . Trichosioma. 



forming a rounded 



face: . Sericostoma. 



alike in the sexes ; 



last joint ovate : . Rhyacophila. 



filiform: Hydropsyche. 



not folded. 



Antennce stiaceoxxs: . . . Psychomia. 



filiform : . . . Hydroptila. 



• In the 4th volume of the New Series of the Philosophical Magazine — 

 published in February and March, 1834 — are short descriptive notices of some 

 of the indigenous Trichoptera, by Mr. Curtis, whose names I have endea- 

 voured to assimilate with my own previously published ones (1829), and with 

 those of M. Pictet ; but it is to be regretted that these descriptions have 

 appeared in a work not devoted to the subject, and consequently rarely seen 

 by entomologists, as the result has been that, from the almost simultaneous 

 appearance of M. Pictet's splendid work on this order (July, 1834), the 



