26 [April 



Easily distinguished from all others known to me by the very dense 

 punctation, especially of the thorax. Much of the pubescence is rub- 

 bed off of the single specimen before me. 



1?.. 0. frigida. Smith. 



Osmia frigida. Smith. Brit. Mus. Cat. i, p. 142, % 9. (1854.) 



" Female. Length 5 lines. — Black, the head has an ochraceous pu- 

 bescence, which is dense on the face, and sparing on the cheeks and 

 vertex. Thorax, the disk thickly clothed with ochraceous pubescence, 

 the femora have a thin fringe beneath of the same color, on the tibi)« 

 and tarsi it is fuscous ; wings subhyaline, their apical margins faintly 

 clouded ; the two basal segments of the abdomen thinly clothed with 

 ochraceous pubescence ; on the third, fourth and fifth it is black ; the 

 apical segment covered with very short ochraceous pubescence ; be- 

 neath it is dense and black. 



" Male. Length 3—1 lines. — The clypeus covered with long white 

 pubescence, on the vertex and disk of the thorax it is long, thin and 

 pale ochraceous ; the base of the abdomen has a little scattered long 

 pale pubescence, otherwise it is short, sparing and fuscous ; the margin 

 of the fifth segment fringed with brown pubescence ; the sixth segment 

 has down the middle a shallow longitudinal channel; the apical mar- 

 gin entire. 



" Hah. — Hudson's Bay." 



Unknown to me. 



14. 0. bucconis, Say. 



Osmia bucconis. Say. Bost. .Jourii. Nat. Hist, i, p. 400, % 9- (lf'-57-) 



•' Female. — Body black, with rather short gray hairs, and obvious, 

 dense punctures : head rather large, long between the eyes and thorax: 

 nasus entire : mandibles with a patch of dense prostrate hairs near the 

 tip : wings hyaline: nervures fuscous; wing-scale piceous : tergum with 

 short, blackish hairs ; segments rather convex, narrow, white bands of 

 prostrate short hairs, wider each side ; towards the posterior extremity 

 with numerous white, short hairs, obvious in profile ; jjosterior tarsi 

 with longer hairs, tinted with ferruginous ; venter with fulvous hairs. 

 Length over three-tenths of an inch. 



" Male. — Resembles the female, but is smaller, and the tail has four 

 distant denticulations. Length one-fourth of an inch. 



*• Hah. — Indiana." 



