Insects. 3255 



the graining of pine-wood. The cocoons are attached to the ridges 

 and roughnesses of the stone. Taking these circumstances into con- 

 sideration, I arrive at the following conclusions : — This species lives 

 in communities, after the manner of Anthophora ; and the empty co- 

 coons indicate the fact, that a number of these bees must have fre- 

 quented the same spot during a succession of seasons: the number of 

 closed cells, when found, being at least double that of the empty ones, 

 indicates that several bees deposited their eggs in close approxima- 

 tion. As no covering of any kind was constructed over the mass of 

 cocoons, the parent bees doubtless attached their little masses of pol- 

 len and honey to the roughnesses of the stone; these could not have 

 been more than three-eighths of an inch apart, or scarcely so much, 

 in order to allow for the number of cocoons in the space which they 

 occupied. The cocoons out of which the Chrysis emerged were pre- 

 cisely similar to those which contained the bees ; and from this cir- 

 cumstance I am led to conclude that the larvse of Chrysis fed on the 

 pupae of the bee after it had spun its cocoon : I have elsewhere shown 

 that this is the habit of a parasitic insect belonging to the Chalcididae, 



Monodontomerus ? which feeds on the pupa of Anthophora, 



and not on pollen. 



Our Osmia is the bee described by Zetterstedt in the 'Insecta Lap- 

 ponica,' as Anthophora inermis. In a note added to the description, 

 it is stated that a nest was found under a stone, and that there were 

 twenty-two cells attached to it. On their being opened, some were 

 found to contain perfect bees, and others Chrysis Austriaca ? 



The females of Osmia parietina, O. xanthomelana, O. fusciformis 

 and O. pilicornis, closely resemble each other, I therefore embrace the 

 opportunity of pointing out a few additional specific differences. O. 

 xanthomelana is the largest species; the pubescence on the face is 

 long, black, and dense; and the bee varies in being from 5 to 6j lines 

 in length. O. pilicornis most closely resembles xanthomelana; it has 

 black hair on the face, which is thin, and the insect is only 4 lines in 

 length. O. parietina has fulvous pubescence on the face, and that on 

 the base of the abdomen is also fulvous, thin, and occupies only the 

 basal segment, or sometimes extends a little on the lateral margins of 

 the second. O. fusciformis is very like xanthomelana, and in size 

 stands intermediate between that species and pilicornis ; its abdomen 

 however differs from both species in being narrowed towards the base. 

 The characters whereby to distinguish the males are sufficiently given 

 in the descriptions of the species. Frederick Smith. 



September, 1851. 



