British Species of Caddis-flies. 153 
semilunate spot more towards the costa; fringes pale yellowish ; 
in the female these wings are much paler and the yellowish spots 
are indistinct. Posterior wings smoky-grey with concolorous 
fringes. Legs greyish-ochreous, paler in the female. Abdomen 
dark blackish-fuscous, slightly paler beneath. In the male there 
is a long straight narrow yellow lobe from the upper margin of 
the last segment, the apex of which is truncated ; app. sup. very 
small; app. inf. very long, yellow, cylindrical, the tips approxi- 
mating. ' 
Expanse of fore-wings, ¢ 6—7 lines, 2 9—10 lines, 
A common species in many localities, frequenting canals and 
slowly-flowing rivers. In Ireland it is abundant near Dublin and 
also at Killarney. It is wanting among the Stephensian types, 
but exists in Curtis’ Collection under the MS. name of memo- 
rabilis. This insect is very widely distributed, Dr. Hagen having 
even received it from the Slave Lake in North America. 
Fam. RHYACOPHILIDA. 
Antennze moderately stout, as long as, or shorter than, the 
wings; ocelli generally present; maxillary palpi alike in the 
sexes, scarcely hairy (except in Berea), the last joint usually 
cylindrical ; anterior wings usually with but slight hairy clothing, 
broad and dilated towards the apex ; posterior wings generally 
broad and folded ; legs nearly spineless, but furnished with long 
spurs, varying in number in the different genera. 
Larva elongate, decreasing in size at the extremitics; head and 
pronotum corneous ; mesonotum and metanotum of the same con- 
sistency as the abdomen; legs short; first abdominal segment 
without protuberances, terminal segment provided with long anal 
hooks ; respiratory filaments arranged in tufts, or these filaments 
are entirely absent externally. 
Pupa elongate; mandibles internally dentate; abdomen not 
fringed at the sides, without external respiratory filaments. It is 
contained in an oval cocoon within the case, the cocoon being 
composed of a gelatinous material which hardens into a tough 
membrane. 
Case a fixed heap of small angular stones placed beneath a 
large stone. The larve live almost free beneath stones, retir- 
ing into the cases on the approach of danger and when about to 
assume the pupa state. 
Most of the genera frequent swift streams. 
