
AQUATIC INSECTS OF FRESHWATER 

ing patterns and shades in brown. It may be seen on the wing in early 
summer, deposits its eggs, encased in a gelatinous capsule, on the under 
side of floating leaves near the edges. The larve burrow into the leaf 
until too large to find a refuge, when they bite off oval pieces and fasten 
them to other parts of the leaf with a gelatinous secretion or silk; and in 
this secure retreat the molts take place. The more general species are 
H. obliteralis, Fig. 232, which lives on water plants in greenhouses, rarely 
out-of-doors, H. albalis, H. allionealis, A. ekthlipsis, H. icciusalis, H. 
obscuralis, H. stenialis, and six other species on the Atlantic slope of 
the United States. 
Cuina-Marks or Caractysta are small moths, rarely over 54 inch 
spread of wings, of which those of the male are white, with black mark- 
ings and of the female brownish with darker markings. The larva is 
brownish and is most often found among the duckweed, of which it spins 
together the leaves to form a casing. The more general species are C. 
fulicalis, Fig. 232, and C. difascialis, with three other species not so 
generally distributed in the United States. 
There are several other genera of Lepidoptera which are semi-aquatic 
but which are not generally distributed and need not be mentioned here. 
Orper Aricunip#. This order, consisting of the spiders, scorpions 
mites and harvest-men, possesses certain characteristics in common with 
the Crustaceans with which it is allied. All the families have a com- 
bined head and thorax, a globular, ovate, cylindrical 
or triangular abdomen connected by a slender waist; 
eight legs attached to the thorax, and simple eyes, 
varying from 2 to 12 1n number, placed in two trans- 
verse rows. The mouth parts are armed with 
powerful forceps to seize, hold and poison their 
prey, below which is a pair of maxilla, somewhat 

resembling a pair of legs. The spinning organs 
are situated at the tip of the abdomen and the, 
FIG. 233. Aquatic-Spider, 
rgvroneta aquatica. Abdomen 
Breathing apparatusisat the forward portion of the ‘sounded with air. | Enlarged. 
abdomen. It serves the purpose of lungs, the colorless blood circulates 
around and through it and is aerated by the absorption of air. There is 
no metamorphosis, as the young, just issued from the egg, exactly resembles 
the adult. Molting continues after the spiders have reached the adult 
stage. All the aquatic genera belong to the Senoculina, or six-eyed group. 
One species, Argyroneta aquatica, Fig. 233, about 3, inch long, spins a 
baglike web of silk half the size of an acorn among the water plants with 
the opening below the surface, and lives in it under the water, taking a 
bubble of air into it each time it comes to the surface; effected by erecting 
273 
