HYMENOPTERA. 193 



claws ferruginous. Abdomen short, broad and slightly convex 

 above, the segments have narrow pale marginal fasciae, usually 

 much interrupted on the three basal segments ; beneath, the 

 pollen-brush is of a golden-yellow. 



Obs. This insect is probably the female of M. frigida, 

 having been captured in various and the same localities as that 

 species. 

 Hab. North America (E. Doubleday, Esq.) ; Nova Scotia (Coll. 



Lieut. Redman). 



150. MEGACHILE FRIGIDA, n. s. B.M. 



Male. Length 5-6 lines. Black, the face densely clothed 

 with bright yellow pubescence, the apical joint dilated and com- 

 pressed ; the disk of the thorax thinly clothed with ochraceous 

 pubescence, that on the sides and also on the sides of the basal 

 segments of the abdomen is pale ochraceous ; the anterior legs 

 pale testaceous, the apex of the femora and the tibiae above, ex- 

 cept its apex, rufo-fuscous ; the tarsi broadly dilated, and having 

 beneath a dense fringe of yellowish-white pubescence ; the first 

 joint of the tarsi has above a narrow fuscous fringe ; the femora 

 beneath have a long loose fringe of nearly white pubescence ; 

 the intermediate tarsi covered with pale yellow pubescence, and 

 having a long loose fringe behind of the same colour ; the pos- 

 terior tibiae curved. The apical segments of the abdomen curved 

 beneath, the margin of the apical segment serrated and deeply 

 notched in the middle. 



Obs. This species very closely resembles the European one, 

 M. maritima, from which it differs in wanting the black spot on 

 the second joint of the anterior tarsi beneath, and in not having 

 the mandibles yellow on their inferior margins; the posterior 

 femora are also much less thickened and the posterior tarsi con- 

 siderably longer. 

 Hab. United States (Coll. E. Doubleday) ; Nova Scotia (Coll. 



Lieut. Redman) ; Arctic America (Coll. Sir John Richardson) ; 



Canada (G. Barnston, Esq.). 



151. MEGACHILE BUCEPHALA, n. s. B.M. 



Female. Length 6 lines. Black and elongate, head qua- 

 drate, the face having on each side a little griseous pubescence ; 

 the anterior margin of the clypeus produced in the middle, and 

 having on each side a short blunt tooth ; the mandibles very 

 stout, roughly sculptured above, and deeply channeled towards 

 their apex, which is armed with two teeth, the apical one long 



K 



