of some South Brazilian Triclioytcra. 141 



powerful and curious forceps ; the femur is veiy thick, and 

 has on its distal inferior angle a stout process, resembling 

 the thumb on the hand of a crab ; the tibia and tarsus are 

 extremely short, so that the curved claAV impinges against 

 the process of the femur. The cocoon of the pupa, also, 

 is not protected by a i-egular case ; sometimes there are 

 some loosely-connected stones around it, but at other times 

 it appears to lie, without any special protection, between 

 the Podostemece. The feet of the first and second pair of 

 legs are provided in the pupa with strong well-developed 

 claws, which I have not yet seen in any other Trichopterous 

 pupa. They are, probably, very useful to the pupa of 

 this species, which has to make its way between the 

 densely-intricate stems of Podostemeoi. 



Genus II. 



The larvfB of some smaller species oi RhyacophilidcB build 

 portable cases, agreeing with those of most HydroptilidcB 

 in not showing any difference between the two extremities. 

 They are built of stones, oval, Avith a flat bottom, on either 

 end of which there is an opening ; the stones generally 

 being of comparatively large size, the external aspect is 

 often very irregular. As the two doors of these little 

 stone-houses are in the flat bottom, they would not fi-eely 

 admit the Avater necessary for respiration, when the larva 

 is at rest, and there are special contrivances for the access 

 of Avater A'arying in the several s{)ecies. In one species, 

 frequenting small mountain • riAailets, small passages are 

 left betAveen the stones of the dorsal side of the house. 

 In another species, which often covers by countless 

 thousands the stones in clear streams, an upright cylin- 

 drical chimney, made of grains of sand, rises from the 

 middle of the house ; its height sometimes equals, or even 

 exceeds, the length of the house. When the larva is about 

 to change, the bottom and chimney are removed, the 

 borders of the vault are fixed to the stone, on which it 

 lives, and then a cocoon of the usual form is spun. 



HYDROPTILID.E. 



In Hagen'slist of South American Neuroptera( Synopsis 

 of the Neuroptera of North America, 1861, p. 299), no 

 species of this family is mentioned, and yet it Avill j)robably 



