CADDIS-FLIES 265 



Limnophilus rhombicus is somewhat larger than 



L. lunatus, and has a snuff- 



Limnophilus brown coloured body and well- 



rhombicus. marked brownish wings. The 



same pattern, No. 33, will serve 

 for both of these species. The larva of L. rhombicus 

 makes a quadrilateral case of vegetable matter or of 

 shells, sometimes of both ; it is shown at Fig. 51. 



Fig. 51. LiMNOPHiT.us rhombicus x 3 (caddis) 



The black silverhorns {Mystacides nigra or M. 



asurea) are seen in great 

 Black silverhorns. numbers over the surface of 



the stream on warm calm 

 evenings. No doubt the fish feed on them at 

 times, and although they are much darker, and 

 blacker than the small dark sedge, No. 31, I think 

 the pattern would be successful in the dusk or half- 

 light. A marked peculiarity of all the Mystacides 

 is that the fore and hind wings are hooked together 

 in flight. The hooks for this purpose, placed towards 

 the extremity of the anterior margin of the hinder 

 wings, are curiously shaped at the tips, and fit into a 

 narrow fold on the inner margin of the fore wings. 



