302 BRITISH BEES. 



must be for some* use in its economy, is perhaps the most 

 common of all. I have found it in abundance upon old 

 walls with a sunny aspect at Erith, and throughout the 

 pleasant Grays of Kent. It is indifferent as to the choice 

 of its domicile, selecting either walls, where I have chiefly 

 found them, sandbanks, or the decaying stumps of pol- 

 lard-willows. Its processes are similar to those of some 

 of the earlier described, but its larva is longer in full 

 feeding, which, when it has consumed all its provender 

 spins a tough cocoon of brown silk, wherein it under- 

 goes its changes ; some, depending much upon locality, 

 pass into pupae in the autumn, others hibernate as larvre 

 which are subject to destruction from the attacks of the 

 Chalcideous insect, Monodontomerus denlipes, previously 

 noticed under Anthophora. Some of the Chrysididae 

 also infest several of the species of this genus, and I have 

 no doubt that Stelis aterrima is parasitical upon one of 

 them, although it has not been recorded. The various 

 species frequent many flowers, especially those abundant 

 in the locality they inhabit, but the 0. pilicornis chiefly 

 affects the common Bugle (Ajuga reptans), and they 

 much frequent composite flowers, especially the species 

 of the genus Hieracium. 



Section 2. Cenolites (dwellers in community). 



Subsection 1. SPTJKBED. 



f Parasitical. 



Genus 25. APATHUS, Newman. 



(Plate XV. figs. 1 and 2.) 



APIS ** e 2 partly, Kirby. PSITHYBUS, St. Fargeau. 

 Gen. Char.: BODY subhirsute. HEAD subglobose; 



