OSMIA. 301 



very pretty but extremely common species the 0. mnea, 

 in which the male is of a rich bronzy tint, and the female 

 of a beautiful blue, verging sometimes to nearly black, 

 burrows also in wood, although sometimes it capriciously 

 selects old walls or chalk-cliffs, and is subject to the 

 incursions of the same parasite. Perhaps the most 

 extraordinary species is the 0. parietina, figured and 

 named by Curtis, and which he first found at Amble- 

 side ; it has since been found in the Grampians very con- 

 siderably above the level of the sea, and it is thus essen- 

 tially a northern species both from altitude and locality. 

 It would appear that this species selects some flat stone 

 of about a foot in surface, lying upon the ground over 

 a hollow spot. Such a specimen, sent to the British 

 Museum, had attached to its under side two hundred and 

 thirty cocoons, indicative of a considerable colony, or 

 perhaps the accumulation of successive years, as one- 

 third of these cocoons were empty of tenants. These, in 

 their new depository, continued developing themselves 

 in the perfect state between March and June, males ap- 

 pearing first. When the transformations of the season 

 ceased, five-and-thirty were still left to present them- 

 selves another year, and the following spring these were 

 developed ; thus, including those which had already 

 escaped when the stone and its treasure was secured, 

 three successive seasons were occupied in their trans- 

 mutations. It may be a species that requires three 

 years for its metamorphosis, and the whole deposit of 

 cocoons may have been the result of three years' accu- 

 mulative structure, the vital activity of their northern life 

 being perhaps more sluggish than in species frequenting 

 the south. The last species the 0. rufa, that in which 

 the female is remarkable for its inverted horns, which 



