140 HYMENOPTERA. 



Harris' MS. notes, was found in tlie perfect state in cocoons 

 within earthen cells under stones, April loth, Tlie cell she con- 

 structs is half an inch long, oval, cylindrical, and contracted 

 slightly into a sort of neck just before the opening for the exit 

 of the bee. From Mr. James Angus I have received the pellets 

 of pollen, about the size of a pea, in which it deposits its eggs ; 

 the larvae were about one-third grown in August. 



Tliis species is larger than CMmia simiUima of Smith, while 

 the male antennae are mucli paler, being fuscous. The front 

 of the head is covered with long dense yellow ochreous hairs. 

 The vertex is not of so dark a green as in 0. shniUima, and 

 is covered Avith coarse punctures. The thorax is heavily clothed 

 with yellow ochreous, tliick hairs. The abdomen is yellowish, 

 and nnich more hairy. The legs are stout, fuscous, with yel- 

 lowisli hairs. Length. .35 inch. 



Our smallest and most abundant species is the little green 

 (Mil la siiiu'Uima of Smith. It builds its little oval, somewhat 

 urn-shaped cells, against the roof of the large deserted galls of 

 the oak-gall fly (Diplolepis confluentus), placing them, in this 

 instance, eleven in number, in two irregular rows, from which 

 the mature bees issue through a hole in the gall (Plate 4,* Fig. 

 14. From specimens comnninicated by Mr. F. G. Sanborn), 

 Tlie earthen cells, containing the tough dense cocoons, were 

 arranged irregularly so as to tit the concave vault of the larger 

 gall, which was about two inches in diameter. On emerging 

 from the cell the Osmia cuts out with its powerful jaws an 

 ovate lid, nearly as large as one side of the cell. Both sexes 

 may be found in April and May in the flowers of the willow 



♦Exi'LAXATioN OF PLATE 4. — Fig. 1, a cell of the Humble-bee; natural size, 

 with the ])ollou mass uiion the toj). Fig. 2, end view of the same mass, showing 

 tlic three eggs laid in three divisions of the cavity. Fig. 3, Xylocopa Virginica. the 

 Carpenter IJee. Fig. 4, tlie larva of Xylocopa Virt)i)iica; natural size. F'ig. 5, 

 tlie nest containing flie cells of the same, with the partitions and pollen masses, 

 oil whii'h the young larva is seen in the act of feeding; natural size. Fig. (J, 

 young larva oi Anthrax sinuosn; side view. Fig. 7, pupa oi Anthrax sinuosa, 

 side view; natural size. Fig. 8, the Leaf-cutter Bee (.Aferfarhilc), on a rose leaf, 

 in the act of cutting out a circular piece. Fig. 9, cells of Megachile, in the elder; 

 natural size. Fig. 10, larva of Ccmthm ditpla, the little green Upholsterer Ree: 

 enlarged. Fig. 11, cells of the same in the stem of the elder; natural size. Fig, 

 12, cells of O.swmVj Kf/nivora, new species, the wood-devouring iMason-bce, exca- 

 vated in the maple; natural size. Fig. ]:{, cells of (h/nia simU/imn, the common 

 grei'u Masonbee, built in the deserted gall of the Oak-gall Fly. Fig. 14, a .single 

 earthen cell of the same; natural size. Fig. 15, pollen mass, or bee-bread of 

 Osviia llf/naria; natural size. It is made up of distinct pellets of pollen, which 

 are probably stuck together with saliva. 



I 



