610 Insects. 



late special mission to Brazil. The insect first described belongs to the family of 

 Tenthredinidae, and to the genus Hylotoma of Klug. But this extensive group, as 

 Mr. Curtis has already remarked, affording sufficient grounds for further generic sub- 

 division, he has distinguished the present species by the name of Deilocerus. This 

 genus is most nearly related to Schizocerus, Latr. The species on which it is founded 

 is named by Mr. Curtis D. Ellisii, and is described at length, and the distinctions are 

 pointed out between it and Hylotoma formosa, Klug, to which Mr. Curtis was at first 

 inclined to refer it. Its economy is totally different from that of any other known spe- 

 cies of Tenthredinidae ; the caterpillars of the solitary saw-flies, especially the larger 

 species, forming single oval cocoons of a very tough and leathery material attached to 

 twigs ; and those even of the gregarious species placing their cocoons (which are oval 

 cases of silk and gum) in an irregular manner, with no unity of design. The caterpil- 

 lars of Deilocerus Ellisii, on the contrary, which are evidently gregarious, unite to form 

 on the branch of a tree, an oval or elliptical case, four or five inches long, narrowed 

 superiorly, very uneven on its surface, and of a dirty whitish ochre in colour. The 

 cells, thirty-eight in number in the nest examined, are placed at right angles to the 

 branch, piled horizontally one above the other, unequal in size and irregular in form, 

 those next the tree being pentagonal, the central ones hexagonal, and some of the outer 

 ones nearly round or oval. In one of these cells Mr. Curtis found a dead female, and 

 most of them had the exuviae of the caterpillars remaining, but no shroud of the pu- 

 pae ; he thinks the smaller cells may have been occupied by the males. At the end of 

 each cell is a circular lid, formed of the same leathery material as the rest of the comb, 

 which being cut round by means of the sharp mandibles, leaves an opening through 

 which the saw-flies make their way. In two of the cells were found the dead cater- 

 pillars, which closely resemble those of the genus Hylotoma. The author observes 

 upon the dissimilarity of the mode of formation of this nest to that of any previously 

 observed, the compound nidus (as far as hitherto known) being always the work of the 

 parent insects for the protection of their young through the first three stages of their 

 existence. In this case, however, it is formed by the larvae themselves for the purpose 

 of their own metamorphosis. The nearest approach to this economy seems to be the 

 nidus formed by the maggots of some of the Ichneumones adsciti, whose silken cells 

 are placed regularly in rows. The other nest brought home by Mr. Ellis is that of a 

 wasp of the Fabrician genus Polistes, but differing apparently from any of the species 

 hitherto recorded as forming similar habitations. The nest is attached to a twig, not 

 much more than an eighth of an inch in diameter. It is eight inches long and fifteen 

 in circumference, pear-shaped, and having on its outer margin a hemispherical tuber- 

 cle pierced with a circular hole a little more than half an inch in diameter. The ma- 

 terials of which the nest is composed are very substantial ; and the external undula- 

 tions allow of the tracing of four layers of comb. Many of the neuters fell out on 

 shaking, but neither males nor females were detected. The specimen being unique, 

 Mr. Curtis has not cut it open, but he entertains no doubt that its structure is very si- 

 milar to that of the nest of Polistes nidulans, figured by Reaumur. The insect is 

 named Myraptera brunnea by Mr. Curtis. — From the 'Proceedings of the Linnean So- 

 ciety,' i. 186. 



Notes on the Habits of Hylesinus Fraxini, (Fab.) The family of bark beetles (Sco- 

 lytidae) appears to have occupied a good deal of the attention of entomologists, partly 

 from the interesting nature of their habits, and partly from their powerful and injuri- 

 ous agency in the destruction of park and forest timber. The histories of many spe- 



