The Mason-bees 



ous visitors. Lastly, to complete the enu- 

 meration of the Bees known to me as making 

 their homes In the Mason's cupolas, I must 

 add Megachile apicalis, who piles in each cell 

 a half-dozen or more honey-pots constructed 

 with disks cut from the leaves of the wild 

 rose, and an Anthidium whose species I can- 

 not state, having seen nothing of her but her 

 white cotton sacks. 



The Mason-bee of the Sheds, on the other 

 hand, supplies free lodgings to two species of 

 Osmise, Osmia tricornis, Latr., and Osmia 

 Latreillii, Spin., both of whom are quite com- 

 mon. The Three-horned Osmia frequents 

 by preference the habitations of the Bees that 

 build their nests In populous colonies, such 

 as the Chalicodoma of the Sheds and the 

 Hairy-footed Anthophora. Latreille's Osmia 

 is nearly always found with the Three-horned 

 Osmia at the Chalicodoma's. 



The real builder of the city and the ex- 

 ploiter of the labour of others work together, 

 at the same period, form a common swarm 

 and live in perfect harmony, each Bee of the 

 two species attendmg to her business in peace. 

 They share and share alike, as though by tacit 

 agreement. Is the Osmia discreet enough not 

 268 



