Animals of the Mississippi Bottoms near Quincy. 171 



one side, sometimes to two sides, is a long rootlet or twig of a 

 weed that may project at one or both extremities some distance 

 beyond the case. The larva is plain white, with the head 

 mottled with yellow and deep brown. Along the sides are 

 attached fleshy respiratory filaments. The usual tubercles and 

 hooks for adhering to the case are present. It swims by strik- 

 ing the water with the very long and heavily fringed hind legs, 

 these being projected beyond the large opening for this 

 purpose. 



Trichoptera, larva (2). 



A second larva lives in a short, conical case about .25 inch 

 long, with a diameter of .125 inch at the larger and of .06 inch 

 at the smaller end. The outer surface is thickly covered with 

 bits of dead vegetation, but lacks the long pieces which seem 

 never to be absent from the other cases. The larva also is short 

 and stout, but is not otherwise very different from (1). The 

 posterior legs are not so long and slender relatively and the 

 fringe is less perfect. This form was taken from the bottom 

 in Willow Slough. 



Trichop)fera, pupa. 



A pupa of some species of this group was taken in Willow 

 Slough sealed up in its cylindrical case of dead vegetable 

 materials. At the end towards which the head lay, a narrow 

 slit had been left for the passage of water for respiration. 

 Judging by the cast larval skin with this pupa, it cannot belong 

 to either of the two larvse described. 



ORDER NEUROPTERA. ( Hellgeammites and Lace-wing 



Flies. ) 



This order contains two families, the larvae of which are 

 very different in habit. The lace-wing flies are throughout 

 life terrestrial, and are well known to gardeners and fruit- 

 growers for the good they do by devouring plant-lice. The 

 hellgrammites or crawlers are aquatic during the larva stage 

 and feed upon other water insects, such as case-fly and May-fly 

 larvae. They are themselves, to some extent, used by sports- 

 men as bait in catching fishes, their tough skin rendering them 



