HYMENOPTERA. 



369 



These nests (Figs. 340 and 341) are filled with cells of oblong 

 form arranged irregularly. At first sight, they might be taken 

 for little lumps of earth plastered against the wall. When the 

 perfect insect emerges, it is obliged to soften the mortar with 

 its saliva, and to remove it, grain by grain, with its mandibles. 

 The nests of Chalicodomas are common in the environs of Paris, 



Fig. 341. Interior of the Nest of the Mason Bee. 



exposed to the south. They are 

 parks of Meudon, of Conflans, of 



3n walls of rough stones 

 Dften to be found in the 

 Vesinet, &c. 



The Leaf-cutting bees (Megachile) are not less worthy of remark 

 in their habits. These insects make their nests in tubes made with 

 the leaves of the rose, the pear, the elder, &c., placed in a cylindrical 

 burrow. Each nest contains generally from three to six cells, sepa- 

 rated by partitions of leaves. They cut oif the pieces of leaves 



Osmia bicornis, a portion of the nest had been forced out by the insertion of the key ; 

 ;he locks were in pretty constant use, so that the nests must have been built in the 

 jourse of a few days. " Journal of Proceedings of the Entomological Society of 

 London," 1867, Ixxvi. ED. 



B B 



