82 JOURNAL OF ENTOMOLOGY AND ZOOLOGY 



also, at times move about in search of building material, for it is 

 unlikely that chance would place enough suitable case-building ma- 

 terial within their reach. 



Larvae which W2re put in the water after they had been exposed 

 to the air until the moisture had dried from their cases, which ac- 

 cordingly floated, swam with their legs motionless and in the atti- 

 tude assumed while waiting for prey. Their motion through the 

 water was caused by the respiratory current being forced through 

 the small openings at the caudal ends of their cases, after the man- 

 ner of locomotion of certain dragonfly nymphs. This was prob- 

 ably an unnatural mode of locomotion, never practiced in nature, at 

 least not by this species. 



Food of the Larvae : The contents of stomachs examined con- 

 sisted of fragments of insects and small Crustacea and two Hydrach- 

 nids, as well as small bits of the tissue of higher plants, some frag- 

 ments of Chlorophycccr and quantities of diatoms of several genera. 

 This miscellaneous assortment of animal and vegetable foods from 

 the stomach, as well as observations on the habits of the larvae, leads 

 us to believe that they will eat any organic matter that floats within 

 their grasp. The combs of fine spines on the legs (Figs. 7, 14 and 

 3), probably serve as plankton sieves, and the long hooked arma- 

 ture of the tarsi (Figs. 7 and 14) certainly suggests carnivorous 

 habits. 



Pupal Habits: In preparation for pupation the larva spins a 

 silken sheet (Fig. 16, C) across the front of the case. This sheet 

 is perforated in the center by a number of small holes arranged in 

 a circle. Surrounding the perforations there is an area which is 

 free from 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 (Fig. 16, B), is spun across 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. 



Period of Emergence: Specimens confined in cages in their nat- 

 ural habitat emerged during the latter part of May and first part 

 of June. No specimens were seen on the wing. 



