British Species of Caddis-flies. 65 
female is more obtuse, and is apparently furnished with two large 
valves which close round and form a tube. 
Larve inhabiting swiftly-running shallow waters. Case com- 
posed in some species of imbricated vegetable fragments, in others 
of small stones, &c.; it is always temporarily fixed. 
The British species comprised in this genus are very discordant 
in size and general appearance, but agree in possessing trical- 
carate posterior tibiz; at the present time only three species 
have been recorded as native, but very many more are known on 
the Continent, though they are for the most part undescribed. 
It is most probable that several others occur among the mountain 
streams of Scotland and Ireland. 
A. Posterior wings of the male not furnished with a pouch. 
1. Halesus digitatus, Schranck. (PI. IV. fig. 5, neuration.) 
Phryganea digitata, Schrk. Ins, Aust. n. 616 (1781); Oliv. 
Encyc. Méthod. p. 556, 8; Pict. (*) Recherch. p. 138, 7, 
pl. 7, fig. 2; Halesus digitatus, Steph. (*) ll. p. 208, 1; 
Kol. Gen. et Spec. Trichop. pt. 1, p. 69,1; Brauer (*), 
Neurop. Aust. p. 47; Hag. (*) Ent. Ann, 1859, p. 95, 387 ; 
Limnophilus digitatus, Burm. Handb. p. 933, 14; Limnephilus 
radiatus, Curt. (*) Phil. Mag. p. 125, 28 (1834); L. htero- 
glyphicus, Curt. (*) Phil. Mag. p. 125, 29 (1834); Lim- 
nephila tessellata, Ramb. Hist. Névrop. p. 478, 10 (1842). 
Antenne and palpi reddish-testaceous. Head testaceous, some- 
what fuscescent. Mesothorax testaceous in the middle, shining 
blackish-fuscous at the sides. Anterior wings pale greyish- 
yellow; the veins of the anastomosis, and usually those of the 
apex, broadly margined with grey; long grey streaks in the 
apical cells, and between most of the longitudinal veins, some- 
times forming large grey blotches; costal margin unmarked. 
Posterior wings hyaline, yellowish at the apex, and with yellow 
veins. Legs ochreous, with black spines. Abdomen greyish- 
fuscous above, paler beneath, 
Expanse of fore-wings 18—23 lines. 
Larva frequenting running waters. Head and thorax brown, 
with black markings, forming somewhat regular figures; on the 
head are a number of small raised black lines. Thorax granu- 
lated with black, darker in the middle, and with two stripes pos- 
teriorly. Mesothorax with a longitudinal fawn-coloured line ; 
varied with brown and black. Abdomen yellow, with few respi- 
ratory filaments. Feet strong and fawn-coloured. (Pictet.) 
VOL. V. THIRD SERIES, PART I.—ocT. 1865, F 
