Notes on the Cases of some South Brazilian Trichoptera. 7 5-7 



loosened the covering, would hardly be able to creep out of their tubes, and, if 

 they succeeded in doing so, the tender, fragile creatures would almost infallibly 

 be crushed. But now, after loosening the covering which remains fastened to the 

 rock, they are within their tubes safely carried away by the water to some quiet 

 place, where they may with leisure creep out and undergo their final trans- 

 formation. The pupa is remarkable for its last abdominal segment being unusually 

 long (as long as the three preceding ones), and tapering towards the end. Number 

 of dorsal patches as in Helicopsyche, each patch armed with two short, sharp teeth. 



Genus III. Setodes (?). 



There are here three species agreeing in general appearance and in the 

 neuration of the anterior wings (one of them even in colouring) with Setodes 

 punctata and viridis; but the posterior wings are broader. 



The larvae, the antennae of which are longer than in any other Leptocerideous 

 larva known to me, live in narrow, cylindrical, straight or slightly-arcuated leathery 

 tubes. Before its change the larva considerably shortens its tube, the ventral 

 side of either end of which is then fixed by means of a disc, usually bilobed, 

 and the extremities closed with coverings having a central circular or elliptic 

 opening. The appendages at the end of the abdomen of the pupa are very long ; 

 the number of the dorsal patches is as in Grumichella, &c., those at the basis 

 of the 4th, 5th and 6th segments have two or three teeth, but those at the basis 

 of the third and at the end of the fifth segments have two pairs of teeth, those 

 of one pair being much smaller. 



In one of the three species the slightly-arcuated brown tubes are covered 

 with very fine sand; the larvae of this species swim very well, their hind legs 

 being furnished with long fringes. The imago is the most beautiful Trichopterous 

 insect I have ever seen. 



In the second species the straight tubes are covered with narrow bits of 

 wood or other vegetable fibres; those on the back are arranged longitudinally, 

 projecting considerably beyond the mouth-end of the tube; those on the sides 

 and beneath are disposed in an oblique direction. 



In the third species to either side of the back of the straigth tube there are 

 fixed a row of bits of wood, projecting laterally, and generally decreasing towards 

 the tail-end. 



Genus IV. 



From the great length of its hind legs I suppose that a little larva, which 

 makes curious nearly cylindrical cases with the seeds of Callitriche, must be 

 placed in this section. 



Section IV. 



The cases of the three species of this section, with the larvae of which I 

 am acquainted, differ from those of all other Leptoceridce by their inner silken 

 tube being much flattened, the height being equal, or nearly so, to half the 

 breadth. The external aspect of the cases is yet much more flattened and broad; 

 for they are covered with bits of leaves, which laterally project more or less 

 beyond the inner tube. 



