274. MODERN CLASSIFICATION OF INSECTS. 
&c.) nidificate in old rotten palings, in which they burrow in an up- 
right direction. The palings in the lane leading from Turnham Green 
to Chiswick are greatly damaged by the last-mentioned species. I 
mention this more particularly, because Réaumur states that this 
species builds its nests in the hollows of large stones. In the first 
volume of the Entomol. Magazine is an account of the habits of O. bi- 
cornis, which is therein stated to nidificate in posts, composing its 
oval cells (about 20 or 30 in number) of clay and sand, glued together. 
In the Insect Architecture (p. 33.) are some observations on the habits 
of this insect. The males appear a considerable time before the 
females. Spinola has given a short account of the history of another 
species of Osmia (O. gallarum, Jns. Lig. vol. ii. p. 70.), which selects 
the abandoned galls of the oak for the place of its nidification, around 
which it glues the leaves, depositing from twelve to twenty-four eggs 
in the cells which it constructs within. In the second volume of the 
Mémoires de la Société de Physique de G'énéve is contained a very 
interesting memoir, by Huber, upon a solitary bee, which he regards 
as the Trachusa aurulenta (Apis aurulenta Panz.), but which agrees 
better with Panzer’s Apis fusca, and which appears to be another 
species of this genus. This insect selects the empty shells of snails 
for the cradle of its progeny.* The history of another wood-boring 
species, apparently of this genus, is given by Wartmann, in Der Na- 
turforscher, stuck xxii. 
The genus Megachile comprises the leaf-cutting, and some other 
bees. The economy of these insects has long attracted the attention 
of the curious; and so early as 1670 it was noticed by Ray, Wil- 
lughby, Lister, &c. Linnzus, supposing that identity of economy 
* This insect is therefore identical in its habits (if not specifically) with Osmia 
helicicola of Rob. Desvoidy, which, together with O. bicolor, was reared by that 
author from nests formed in the deserted shells of Helix nemoralis and H. nomatia. 
(See Comptes Rendus, Acad. des Sciences, 1836, No. 23., for further details; and 
Cyclop. Nat. Hist. vol. ili. p. 360.) 
+ M. Audouin has reared one specimen of a small species of Osmia from the 
first of a series of cells, of which the remainder were filled with spiders, which had 
evidently been there deposited by some fossorial species, the parent Osmia having 
taken advantage of the burrow to form its own cell. Such, I apprehend, was also 
the case with the specimen of Osmia leucomelana, as detected by Mr. Smith, 
entering the dead sticks of the common bramble, from which i¢ might however 
have excavated the pith, but from which he afterwards reared Odynerus levipes 
Shk., which had also made use of the same burrow. (See Shuckard, in Mag. Nat. 
Hist. 1837, p. 491.) 
