SYNOPSIS OF THE BRITISH PHRYGANID.E. 79 



78. Rhyacophila dorsalis, Curt. Phil. Mag. 213 (£); 

 R. vulgaris, Steph. 111. 165, 1 ( $ ) ; R. stigma, 

 Steph. 111. 166, 2 ( <? ) ; R. opaca, Steph. 111. 

 166, 3 ( $ ) ; Phil, longipemiis, Curt. 213 ( ? ) ; 

 Hydrops, angustata, Steph. 111. 174, 9; R. vulgaris, 

 Ramb. 



Ochreous, head darker ; antennae with pale rings ; legs 

 testaceous ; anterior wings dingy-brown, thickly set 

 with small yellow spots ; a larger, rhombic, whitish 

 spot lies like a saddle upon the wings when they are 

 closed ; posterior wings spotless, rather paler. 



Length 5J lin. ; exp. 10 lin. 



Hab. near London, Devonshire, New Forest and Scot- 

 land in June and July. 



In the northern and central parts of Europe there are at 

 least seven species belonging to the group of R. vulgaris, 

 and of these only four are described, namely, R. vulgaris, 

 Pict. ; R. dorsalis, Curt.; R. aurata, Brauer; and R. 

 torrentium, Pict. All are exceedingly similar in form and 

 colour, and very variable in the distribution of the spots, which 

 may even be entirely wanting. The males I can distinguish 

 with certainty by the different form of the app. anales ; with 

 the females this has not succeeded in all the species. When 

 I examined Stephens' type, I was not acquainted with the 

 type of R. dorsalis, and regarded Stephens' species as R. 

 vulgaris, Pict. It is not impossible that this species may 

 occur in England ; at any rate it appeared to me safer to 

 refer these species provisionally to R. dorsalis. 



The app. anal. sup. are two short, horizontal, closely ap- 

 proximated laminas ; close above these there is a narrow 

 band-like lobe, projecting, with its dilated but depressed 

 apex, beyond the app. sup. ; this lobe is attached to the last 



