768 Notes on the Cases of some South Brazilian Trichoptera. 



In the largest species the cases of adult larvae are usually made of four 

 leaves (sometimes there are but three), two forming the ventral and two the dorsal 

 side ; the anterior dorsal leaf is produced far over the ventral one, so as to protect 

 the larva when moving about. This species lives in rivulets. The case of the 

 pupa is fixed at the mouth-end, either extremity of the interior tube being closed 

 with a sieve. 



In the smallest species, which lives on trees between the leaves of Bromelice, 

 there are generally five or six bits of leaves on the ventral, and one more (six 

 or seven) on the dorsal side of the tube. Before its change the larva closes the 

 mouth end by fastening one more bit of leaf to the ventral side. 



This is also done by the third species, intermediate between the other two 

 in size as well as in the number of leaves used in the construction of its case; 

 there are generally three or four on the ventral and four or five on the dorsal 

 side. This species lives principally in very small rivulets, with hardly any water, 

 trickling along a declivitous rocky ground. 



To the different habitat of these three species corresponds a remarkable 

 difference in the feet of the pupae. In the first species there are not only dense 

 fringes of long hairs on the second pair, but similar hairs, though much less 

 developed, exist also on the feet of the fore-legs. These fringes are rather rudi- 

 mentary in the third species, and completely wanting in the Bromelia species, 

 which in this respect agrees with the waterfall Trichoptera. 



The pupae have more dorsal patches than any other of our Leptocerida- ; for 

 there is a pair on the eighth abdominal segment also, and besides this, there is 

 on the back of the ninth segment a pair of long spear-shaped horny processes. 



The first species emerges from the pupa in the evening, as most Lepto- 

 ceridce do, but the Bromelia species usually during the first hours of the after- 

 noon (at least in captivity). The branchiae of the pupa subsist, in a rudimentary 

 condition, in the perfect insect. 



The three species agree, not only in the construction of their cases, in the 

 structure of their larvae and pupae, but also in the neuration of the wings and 

 other characters of the perfect insects (in all the wings the radius is confluent at 

 its apex with the first apical sector; in the posterior wings the discoidal cell is 

 open, the apical forks Nos. 2, 3 and 5 being present). It would be most un- 

 natural to separate them into two genera, and yet they differ in the number of 

 spurs. In the Bromelia species there are 2, 4, 2 in both sexes, while the other 

 two have 2, 4, 4. In any other respect the intermediate species resembles more 

 closely to the Bromelia species than to the larger one, with which it agrees in 

 the number of spurs. 



Hydropsychidse. 



Genus I. Macronema. 



The larva of one species is extremely common, being met with almost every- 

 where under large stones. The larva makes a very rude dwelling with irregularly- 

 accumulated and loosely-connected stones. The case of the pupa is by far more 

 solid and regular, at least when viewed from within. The inner room is oval, 



