180 Mr. M. E. Mosely on British sjpecies of Hydroptila. 



plate are more rounded and the excision is perhaps a Uttle narrower. 

 The penis and the side-pieces of the 9th segment are as in sparsa 

 and shnulans. The inferior appendages have large, flattened extremi- 

 ties turned outwa,rd at a sharp angle to the main stem and terminate 

 in dark, roughened edges. 



The upper margin of the ventral plate has a shallow excision and 

 appears far more strongly chitinised than the rest of the plate. 



Both species are described from examples in Canada 

 balsam and the different aspects are drawn from different 

 examples. 



Explanation of Plate II. 



