CADDIS-WOEMS AND THEIR 3IETAMORPHOSES. 
295 
Psychomyia * (Latr.), maxillary palpi with five joints in 
both sexes, the last long and filiform ; antennse moderate ; an- 
terior wings slender, pointed, without transverse nervures; 
posterior wings slender and without folds similar to anterior 
ones. The larvae, of this genus were not known to Pictet. 
Hydroptila | (Dalman), maxillary palpi with five joints in 
both sexes, the last ovoid ; antennae short, at least as thick at 
the extremity as at the base ; anterior wings slender, bristling 
with hairs; posterior wings not folded, of same form as anterior 
ones. 
Attention to the above characters, which distinguish the 
larvae and perfect insects, will, it is hoped, be of service in aiding 
the student to determine at least the genus of any insect or 
larva he may meet with. For the identification of species he 
must have recourse to the admirable memoir of M. Pictet already 
referred to. 
EXPLANATION OF PLATE. 
Fig. 
o, larva of Phryganea ydlucida ; 6, c, perfect insect ; d, antennae. 
a, larva of Mystacida cylindrica ; h, c, insect ; d, maxillary palpus 
of male. 
a, larva of Tricliostoma fuscicorna ; h, c, insect. 
a, larva of Sericostoma inacula ; 6, c, insect. 
a, larva of Rhyacophila vulgaris ; h, inner membranous case of 
pupa ; c, pupa ; d, insect. 
a, larva of Hydropsyche atomaria ; 6, insect. 
Psychomyia annulicornis. 
a, larvae, in case, of Hydroptila pulchricornis, crawling off a frag- 
ment of water-moss ; h, larva detached from its case ; c, in- 
sect. 
From il/vxv and yvla, ‘^a fly.” 
t From vdu)p and tttlXovj a wing.” 
