NORTH AMERICAN CADDIS-FLY LARV. 
Although, in the Cayuga Basin, the larvee have been found only 
in the McLean region, careful collecting probably will reveal their 
presence elsewhere, for the adults are not uncommon in several 
localities of our uplands. 
Hasits.—During the daytime some larve can always be 
found crawling over the bare stones of the springs they inhabit. 
More larve, however, are to be found attached to the under-side 
of sticks and stones. These larve, like other species of Limno- 
philidz, are nocturnal, except, perhaps, when newly hatched from 
the egg. On this subject Vorhies, ’05, makes the following in- 
teresting observation: ‘The interesting fact was noticed that 
these newly-hatched larve are positively heliotropic to a marked 
degree when on a dry surface, but at once become negatively helio- 
tropic when placed in a dish of water. The necessity of getting 
out from beneath stones where the eggs are placed in order to 
find water, and of getting beneath stones for protection while 
building a case, after reaching it, offers an explanation for this 
peculiarity.” 
In preparing to pupate, unlike the common method of the 
family, the cases of this species are not attached to any object, but 
lie on the bottom of the stream, sometimes under stones and sticks, 
sometimes on the surface of the gravel, but always with the head 
directed upstream. In one habitat of the species the bottom is of 
rather soft muck. In this spring the pupal cases were always 
buried under an inch or more of soil. 
Prepupe and pupe can be found in every season of the year, 
unless, possibly, the early months of winter. Their greatest 
abundance, however, comes during late winter and very early 
spring. 
Foop or Larva:.—To determine the food of the larve, about 
six stomachs of mature larve, and as many of young larve, were 
examined. The stomachs of the young larve contained only 
diatoms, mixed with a large amount of sand—the sand amounting 
to many times the bulk of the diatoms. The stomachs of the old 
larve contained about the same mixture of sand and diatoms, and 
also a few fragments of higher plants. Vorhies, ’05, found the 
food of the old larve consisting of water-cress and water-mil- 
foil, and in 1909 states that the young larve feed upon diatoms. 
In the springs of the McLean region there is a very sparse growth 
