74 THE ENTOMOLOGIST. 



former is a well-known insect in the Alps of Central Europe, 

 where it is common ; that it occurs in the British Isles is 

 extremely doubtful. McLachlan himself latterly held this view, 

 and, I think properly, the species has been dropped from our 

 lists. 



Stephens applied names to quite a number of forms, but of 

 these, C. fascipennis, C. lateralis, C. media, and C. venosa were 

 all swept by McLachlan without question into the synonymy of 

 C. graiiimatica, while C. rufescens of Stephens is also referred 

 to grammatica with a mark of interrogation. 



During many years I have examined a very large number of 

 British specimens of Chloroperla, fresh, dried, and in fluid (spirit 

 and formalin). Although the materials presented a certain 

 amount of variation, there was nothing to seize, and until quite 

 recently I had never seen any British specimens that could have 

 been separated from what has been regarded as C. firammatica. 

 However, Prof. J. W. Carr, of University College, Nottingham, 

 recently sent me a rather important lot of Neuropteroid insects 

 for identification, and amongst these are eight examples of 

 Chloroperla, which, with one exception, are obviously quite 

 different from C. grammatica. Prof. Carr having very kindly 

 given me permission to " mutilate " or otherwise deal with the 

 material as I thought fit, I have been enabled to determine the 

 seven examples referred to as the species to which Klapiilek has 

 applied the name of C. venosa, Steph. (' Die Slisswasserfauna 

 Deutschlands, 1909; Plecoptera,' p. 48). 



Like many of the smaller Plecoptera, the species of Chloro- 

 perla when dried are usually rather troublesome to determine, 

 and they do not possess the complicated genitalia and armature 

 which in Nemoura and Leuctra afford splendid characters when 

 these have been revealed after preparation in caustic potash. 

 These greenish Plecoptera appear, as a rule, to have less chitine 

 in their structure, and as they do not stand caustic well they 

 make less satisfactory balsam mounts. It should, however, be 

 possible to separate the two species of Chloroperla now under 

 consideration, even in a dried condition, and the following 

 attempt to define the differences may be useful. In this I have 

 not confined myself absolutely to the dried specimens, but have 

 also used balsam mounts and examples preserved in formalin, 

 the last-mentioned kindly mounted for me, without further 

 preparation, by Mr. Martin E. Moseley in cells filled with the 

 same fluid, being specially useful. The form of the appendage 

 of the eighth ventral segment in the male, and of the subgenital 

 plate in the female, are of themselves sufficient to separate the 

 two, but in dried specimens these parts will often be found none 

 too conspicuous. 



