CADDIS-FLIES 269 



The number of the spurs on the tibiae is deemed 



of great importance in deter- 



Spurs on tibiae. mining the family and genus of 



the Trichoptera, and I propose 

 in each case giving what is called the spur formula. 

 The spur formula for all the Phryganeidae is 2, 4, 4, 

 which means that there are two spurs on the tibiae of 

 each of the fore-legs, four on each of the medial legs, 

 and four on each of the hind-legs. 



LIMNOPHILID^ 



Of this family in the genus Limnophilus, Anabolia, 

 and Stenophylax the spur formula for both sexes is 



I, 3> 4- 



The following may be taken as fairly plentiful of 



the British insects belonging to these genera : — 



Limnophilus rhombicus, re- 

 Limnophilus. 



ferred to at page 265. 



Limnophilus fiavicornis, very similar to L. rhom- 

 bicus, but not so well marked. The caddis case has 



Fig. 52. Limnophilus flavicornis x 2 (caddis) 



a curious round brush-like appearance, and is shown 

 in Fig. 52. 



