British Species of Caddis-flies. 97 
dense; legs not very long, spineless, or with few and very short 
spines; spurs variable in number in the different genera ; abdomen 
short. 
Larva with the head very small, oval; pronotum rather broader 
than the head, the sides rounded, corneous ; mesonotum much 
broader, also corneous; metanotum still broader, not corneous ; 
first abdominal segment produced into a hump in the middle 
above, and with smaller projections at the sides, the other seg- 
ments subcylindrical, nearly equal at the sides; the respiratory 
filaments very short, placed in tufts of three or four on a common 
base; posterior legs usually very much longer than the others. 
Case usually formed of fine sand, and in shape a cylindrical 
straight or curved tube, generally smaller at one end; sometimes 
formed partly of vegetable matters, and sometimes entirely of 
silk, without any apparent addition of extraneous substances. 
I have found it impossible to tabulate the genera satisfactorily ; 
they may, however, be placed in two divisions, thus :— 
Spurs 2-4-4 . . . « « Odontocerus and Molanna. 
Spurs 2-2-2, 1-2-2 or 0-2-2 Leptocerus, T'rienodes, Mystacides 
and Setodes. 
For more precise information, I must refer the student to the 
detailed characters, and to the outline figures of the neuration. 
Genus Opontocrerus, Leach. 
Antenne moderately stout, longer than the wings, serrated in- 
ternally ; the basal joint stout, as long as the head. Head trans- 
verse. Maxillary palpi hairy, the first three joints stout ; basal 
joint short, second somewhat longer, the remaining three joints 
nearly equal, considerably longer than the second. Labial palpi 
very small, with short basal joint and elongate terminal joint. 
Mesothorax ovate. Anterior wings long, considerably dilated 
towards the apex, which is elliptical ; hairy clothing dense; neu- 
ration strong and distinct; discoidal cell open; in the female 
there is one more apical fork than in the male. Posterior wings 
considerably shorter than the anterior, folded; the anal portion 
more produced in the male than in the female, in which latter sex 
there is also an additional apical fork, as in the anterior wings. 
Legs rather short; anterior tibize with two moderately long, 
equal, apical spurs; intermediate and posterior tibize each with two 
pairs of unequal spurs, Abdomen rather robust; the male with 
well-developed and complicated appendices; the female furnished 
with large superior valves. 
VOL. Y. THIRD SERIES, PART I.—ocT. 1865, H 
