SUBDIVISIONS OF THE AFIDiE. l65 



(149.) The second subdivision of the solitary bees^ the 

 Dasygaatrcp, are thus named from the hirsute clothing 

 of their venter, by which they carry their provisions, and 

 never by their legs, which is the case in all other bees. 

 They constitute a large group, some of the genera of 

 which are very extensive in species, and many of these 

 have received vernacular names. Thus, we have the 

 Leaf-cutter Bees, Megachile, for instance, a very nu- 

 merous genus, extending all over the known world, and 

 tolerably equally distributed. The males of some of the 

 species have the anterior tarsi considerably dilated. It 

 is upon these insects that the coleopterous genus Clerus 

 is probably parasitical. They derive their name from 

 the habit many of them possess of cutting semicircular 

 pieces of leaves from different plants, and with which 

 they line their burrows, usually formed in soft and de- 

 caying wood, whence they have sometimes been called 

 carpenter bees, which is perhaps better restricted to Xy- 

 locopa. It is upon the cognate genus Chelostoma that 

 Mr. Marsham observed the Ichneumon, Pimpla Manifes- 

 tator, which has so largely a developed ovipositor, to be 

 parasitical. In this group there is no genus, excepting 

 only Lithurgus, which does not occur in Great Britain. 



(150.) We have next the Mason Bees, Osmice, the 

 majority of this group form their nests in the third mode 

 we have described above ; and Anthidium, insects gaily 

 marked with yellow bands and spots. In this genus the 

 males are greatly larger than the females, and under the 

 impulse of passion convey her off into the upper air. 

 This genus is further remarkable for the habit it has 

 of lining its nests with the downy coating of plants. It 

 does not, in this country, make its appearance much 

 before the summer solstice. 



(151.) Upon these follow the Cuckoo Bees, which 

 are all parasites ; but although it is convenient to group 

 together a certain number of these on structural accounts, 

 yet shall we find some genera of parasitic bees strag- 

 gling into the following subdivisions that we have to 

 notice. Here we have Melecta, that infests the grega- 



M 3 



