1886.] 147 



to L. hirtum, another quadrangular-case maker, but not to B. suh- 

 nuhilus. The case of B. subnuhilus is one of the most remarkable we 

 have, and it differs much in texture from those of the other two 

 species. 



The larva of C. irrorata is white, with a greenish or yellowish tint. Head, a 

 rounded-oval, with some isolated hairs, uniform dark brown. Pronotum transverse, 

 as wide as head, short, anterior edge straight, posterior rounded ; a few isolated 

 hairs on the disc, and a fringe of long stiff hairs on the anterior margin, which hairs 

 are directed forwards, and slightly upwards ; dark brown. Mesonotum transverse, 

 broader than pronotum, and paler in colour, especially on its posterior part ; a few 

 scattered hairs ; side-pieces, to which legs are attached, darkly marked. Metathorax 

 short, transverse, broader than preceding segments ; a few hairs arising from warts ; 

 side-pieces as in mesothorax. The legs are yellowish, with long hairs ; first pair 

 short ; other two pairs rather long and subequal. The abdomen is nearly parallel 

 on the sides ; along the lateral lines runs a fringe of very fine hairs ; respiratory 

 filaments isolated, and not very numerous, of moderate length ; the last segment is 

 narrower than the rest, and the crochets are brown, and bear some long and very 

 strong black hairs. There are lateral processes on the first abdominal segment, but 

 I cannot make out their true form ; when protruded they show a delicate fringe. 



It is now known that quadrangular cases of three kinds exist in 

 Britain, belonging, as indicated above, to Brachycentrus subnuhilus, 

 Lepidostoma hirtum, and the subject of the present notice. Later I 

 hope to say something about L. hirtum ; the history of B. suhnubilus 

 has been written so well already that it hardly requires supplement 

 (McLach., Eut. Mo. Mag., vol. x, p. 257). 



Hagen appears to have been the first to notice this form of caddis- 

 case, and in the Stett. ent. Zeit., ISGi, p. 113, he refers to what he 

 considers three kinds. Probably his No. 2 belongs to B. subnuhilus, and 

 No. 3 to L. hirtu7n, or an ally. No. 1 is altogether remarkable. It 

 was received from Bremi, who states that he found it amongst moss 

 far from water, and, certainly, the size given, and other points in the 

 description, suggest Crunoecia. The larvae of this insect are not so 

 absolutely aquatic in habit as those of many species ; they can, no 

 doubt, stand total submersion in shallow water, but they crawl about 

 quite freely as long as there is moisture present at all, and in captivity 

 spin up on damp stones, or on the sides of glasses just touching the 

 water. Enoicyla is the only known Triehopterous genus presenting 

 truly terrestrial habits during larval life, and Bremi's declaration is 

 not yet to be explained, unless it is assumed that some unseen driblet 

 existed, which gave the essential, if little, moisture.* 



* Compare de Rougemont (Bull. Soc. Sci. Nat. NeucMtel, xi, 405 — 420) and McLachlaii ;Moii. 

 Rev. Europ. Trich., 1st add. suppl., p. 30), on Helicopsyche. Adkella Jiliconiis in its early stages 

 appears to prefer simple huiaidlty to total submorsiou ; so, too, probably, do all species fro- 

 queiiting siioh places as C. irrorata affects. A small larva, which I take to be that of a IVormuldia, 

 but which I have not yet been able to rear, succumbs very soon if placed in water of any depth, 



N 2 



