246 [December, 



NOTES ON SOME SPETNG-FREQUENTING TRICHOPTEEA. 

 BY KENNETH J. MOETON. 



In one of our glens there is a corner which is well known to some 

 of my Neuropterological friends as one of the few British localities 

 where Drefanopteryx -phalwnoides has been found, and as the only 

 known one for AdiceUa Jilicornis. To those who do not know it, let 

 me explain that this corner lies in a deep gorge with steep, well- 

 wooded sides, and that its situation is perfect as far as protection 

 from cold winds is concerned. From the sides of the glen here, many 

 trickling springs arise, and the water from them, after streaming over 

 moss-grown rock-faces at some points, finds its way into the river by 

 various channels which run through a patch covered with a luxuriant 

 vegetation. Quite a number of the spring-frequenting Triclioptera 

 haunt this spot, and during the summer Criinoecia irrorata, Bercea 

 pullata, AdiceUa Jilicornis, and Diplec/rona felix may all be found 

 together. Having paid some attention to these little caddis-flies I 

 propose to give some account of the habits and cases of the three 

 first-named, which I have reared. 



Cbun(ecia ieeobata, Curt. 



On the wet rock-walls, amongst the moss which in some places 

 covers them, and in the small channels which draw off the water to 

 the river, may be found cases from 6 to 8 mm. in length, made of 

 small square plates, cut out of fresh or dead leaves or moss, sometimes 

 mixed with fibres placed transversely. The plates and fibres are neatly 

 cemented together, so as to form perfectly quadrangular cases. As 

 already recorded (vol. xxii, p. 43), these cases are the work of the 

 larvae of C. irrorata. 



But the cases of C. irrorata are not always quadrangular : very 

 junior larvro inhabit cases which are almost perfect cones made of 

 sand grains, rather rough externally ; and examples may often be 

 found in a transition state — mouth-end quadrate, made of vegetable 

 matter ; tail-end consisting of the sand-cone with the apex cut off. 

 There is before me one taken from a rock-spring the other day, and 

 of a length of 8 mm. : 5| mm. is composed of vegetable matter, 

 arranged in the usual way, while the rest is made of sand. In another 

 the proportions are just about reversed. So, while the gradual change 

 appears to be usual, it is possible that under certain conditions the 

 sand-case is persistent, simply increasing in size, and becoming less 

 attenuated towards the tail-end — a conjecture which applies equally 



