NOTES ON BRITISH TRICHOPTERA. / 



quadrangular cases (Trichop. Brit. pi. ii. fij^. 34), vet re- 

 mains undecided. That it contains at least two British 

 species is rendered tolerably evident, by cases in my collec- 

 tion ; these presenting differences in size, and in the materials 

 employed, sufficient to cause it to appear that the two forms 

 could not have been constructed by one and the same species. 

 In conclusion I will glance at local considerations. Any 

 district, diligently worked, will no doubt produce a due 

 share of novelties, supposing the observer to have obtained 

 the experience which these, and all other insects, require for 

 successful capturing. Yet two extensive portions of our 

 kingdom merit especial attention. One of these is the 

 north of Scotland, from Perthshire northwards, including 

 the islands, a district which must possess many, yet undis- 

 covered, Scandinavian forms. My own visit to Perthshire 

 was made too early in the season to afford any adequate idea of 

 the productions of the Highlands : July and August would 

 be the best months. The other district is the south-west of 

 Ireland. The insect fauna there is already known to ap- 

 proximate, more closely than elsewhere, to that of the Iberian 

 peninsula, and an additional evidence exists in my own col- 

 lection, in an example of a May-fly, JBa'ctis Jiavidus of 

 Ed. Pictet, from Killarney. So I anticipate that when a 

 Neuropterist shall work this locality in earnest, he will reap 

 an abundant reward. 



Forest Hill, London, 

 Aih November, 1867. 



