SERICOSTOMATIDE. 
perforations. At the caudal end of the pupa (about two-thirds 
the length of the case from its cephalic end) a second sheet of 
silk, figure 148 B, crosses the case. This second sheet resembles 
the first, except that the circular area of perforations is larger. 
Pupation takes place on the exposed areas on sticks or stones 
where the larval life was spent. 
PERtop oF EMERGING.—Specimens confined in cages in their 
natural habitat emerged during the latter part of May and first 
part of June. 
Foop oF THE LARvai.—According to Miss Helen Murphy, 
who followed the species from the egg to the adult, “the cases 
are completed in about five hours. The larve then start to eat. 
For the first two weeks the food consists entirely of diatoms, 
such as Meridion, Cymbella, Navicula, Cocconema, Fragilaria, and 
Synedra. This food they obtain by browsing on the stones and 
vegetation, over which they hastily scramble. At the end of the 
third week the green alge Oedogonium, Cladophora, Ulothrix, 
Cylindrospermum, and bits of seed plants are added to the diet.” 
“At the end of the sixth week the larva is about three-six- 
teenths of an inch in length.” ‘From a purely herbivorous diet, 
obtained by active searching, they now become mainly carnivorous, 
waiting in a most receptive attitude for whatever may come 
within their powerful grasp.” “An examination of their stom- 
achs at this time reveals quantities of fragments of mayflies, Hy- 
drachnids, Chironomids, and Crustacea, as well as Chlorophycez 
and diatoms of several genera. ‘This miscellaneous assortment of 
animal and vegetable foods from the stomachs, as well as observa- 
tions on the habits of the larve, leads us to believe that they will 
eat any organic matter that floats within their grasp. The combs 
of fine spines on the legs (figures 134, 140, and 146) seem to serve 
as plancton sieves, and the long, hooked armature of the tarsus 
certainly is adapted to a carnivorous diet.” 
DESCRIPTION OF THE Larva.—The length of the mature larva, 
figure 133, is about 12 mm.; its breadth is about 2.5 mm. In life 
the soft parts are green; the heavily chitinized parts are dark- 
brown, appearing black when viewed in reflected light. The ab- 
domen tapers gradually from the first to the last segment. 
The Head—rThe head is black, marked with brown on the 
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