50 Bulletin No. 159 



closed by a thin flexible brown concentrically striate silken 

 disc, each with an excentric curved slit. Pupae were already 

 formed in some of them, lying with the head just behind the 

 disc. Other specimens were collected in Elkhorn Creek, 

 near Lexington, July 4, 1890, and at Elk Lick Falls, July 14, 

 1893. The late A. S. Packard named the species producing 

 a spiral shell in New England, Helicopsyche glabra, but in 

 the American Naturalist for 1869, p. 160, quotes Hagen as 

 pronouncing it H. borealis. Hagen in the same connection 

 states that he thinks a species described by Lea, the con- 

 cologist, as Valvata arenifera, from the Cumberland River, 

 near Nashville, is different. Ulmer in "Genera Insectorum" 

 lists Lea's name as a valid one. It was used by Lea in the 

 Transactions of the American Philosophical Society, Vol. 4, 

 p. 104, 1834. There is some reason for thinking that the 

 Kentucky material represents the supposed snail described 

 by Lea. Judging by Packard's description and figures the 

 case of the Kentucky insect differs from that of H. borealis 

 in being composed of much coarser material, and the silken 

 disc spun in the aperture before pupation appears to lack 

 the slender teeth which he says project from each side over 

 the slit and form an imperfect grating. 



The pupa is enclosed in a thin pellicle, probably cast 

 when the adult emerges. A sharp tooth projects forward 

 from the mouth. Eyes conspicuous. The long antennae and 

 legs lie free along the sides of the body. On the back of 

 the abdominal segments are short spines, some projecting 

 backward and the others forward, probably of service in 

 getting out of the shell finally. The long body is curved to 

 fit the shell and bears a bar and tuft of hairs at the end. 

 Length about 6 mm. 



Case-fly Larva No. U. —A third larva resembles the pre- 

 ceding in general structure, but is provided with branched 

 appendages of respiration on the ventral side of the body. 

 While the surface everywhere is rather densely pubescent, 

 the last segment bearing a pair of long, clawed, false legs, 

 each with a brush of long plumose hairs, generally loaded 

 with dirt and often bearing living stalked Protozoans, which 



