134 Dr. Fritz Miiller's Notes on the Cases 



brancliife of the pupa subsist in the imago in a rudimentary 

 condition. 



There are here two species of this genus, differing much 

 in size, the larvfe of Avhich live in clear rivulets ; a third 

 species of larvae, building unusually short and wide tubes, 

 of which I have seen but very few specimens in the River 

 Itajahy, probably belongs to the same genus. 



Genus II. Grumicha, of Saint Hilaire. 



The wings having no median cell, the insect cannot be 

 placed in M'Lachlan's fourth section, while, by the mode- 

 rate length of the antennas and the presence of the apical 

 fork. No. 2, in all the wings it is excluded from Section III. 

 Thus I place it here, though it shows no particular relation 

 to Odontocerum. (Spurs 2, 2, 2. Discoidal cell closed, 

 and radius connected to the first apical sector by a trans- 

 verse nervule in all the wings. Apical forks, Nos. 1, 2, 3, 5 

 in the anterior, 1, 2, 5 in the posterior, wings.) The well- 

 known black Dentalium-like tubes of the larv^ are fre- 

 quent in some of the larger tributaries of the Itajahy. The 

 larvae are remarkable for the tibite of the hind legs con- 

 sisting of two joints. The tail-end of the tube is closed 

 with a transverse wall, having a central circular opening. 

 Before its change the larva fixes the mouth-end of its tube 

 by a petiolated disc to some stone or to other tubes of the 

 same species. Clusters of more than a hundred specimens 

 are sometimes found. The mouth-end of the tube is closed 

 with a circular covering, provided with a transverse open- 

 ing beneath its centre. 



SECTION III. 

 Genus I. Tetracentron, Brauer. 



One species of this New Zealand genus is extremely 

 common here. The larva, Avhich, like those of Grumicha, 

 have two-jointed tibije on the hind legs, lives in sticks of 

 Avood, fi-agments of branches, of petioles of Cecropia 

 leaves, &c. These are hoUoAved out in couA^enient lengths, 

 and a semicircular piece is cut away from the Acntral side 

 of the mouth-end, so that the dorsal side projects, pro- 

 tecting the larva Avlien craAA^ing about ; besides this, for 

 more protection, a small stone is fastened to the project- 

 ing dorsal side, Avhich closes the entrance Avhen the larA^a 

 retires into its case, and covers its head Avheu feeding. 



