HYMENOPTERA. 143 



thorax, setaceous, fulvo-testaceous beneath; the face thickly 

 covered with long white pubescence, a similar pubescence is also 

 more thinly scattered over the vertex, thorax and base of the ab- 

 domen ; wings as in the female ; the apical segment notched in 

 the middle ; Iseneath, the ventral segment is bidentate. 



Obs. This species very closely resembles the Osmia ccerules- 

 cens ; the female is difficult to distinguish ; it differs in being 

 larger and of a brighter blue, and in wanting the smooth, shining 

 space below the post-scutellum always present in 0. cmrulescens. 

 The male differs in the form and pale colour of the antennae 

 beneath, and in the margin of the apical segment being deeply 

 notched in the middle and entire laterally. 

 Hob. Nova Scotia; U. States. (Coll. Lieut. Redman.) 



51. Osmia chalybea. B.M. 



Female. Length 6 lines. — Steel-blue, head very large sub- 

 quadrate, and thorax strongly and closely punctured, the abdo- 

 men more finely so ; the anterior margin produced in the middle, 

 the apex of the lobe emarginate, the margin on each side is cre- 

 nulated ; the mandibles very large, a deep groove running along 

 their inferior margin from the apex to the base, where it termi- 

 nates in a pit or hollow. Thorax, the sides thinly covered with 

 griseous pubescence ; wings fuscous, palest towards the base ; 

 the sides of the abdomen fringed with short griseous pubescence ; 

 beneath densely clothed with black pubescence. 



Male. — Closely resembles the female, the margin of the elypeus 

 in this sex is entire, and the margin of the apical segment notched 

 in the middle ; beneath, the ventral segment bidentate. 

 Hah. St. John's Bluff, East Florida. (E. Doubleday, Esq.) 



52. Osmia bucconis. B.M. 

 Osmia bucconis, Say, Bost. Journ. Nat. Hist. i. 400. 2. 



Hab. United States. 



53. Osmia lignaria. B.M. 



Osmia lignaria. Say, Bost. Journ. Nat. Hist. i. 399. \. 

 Osmia purpm-ascens, Smith, Zool. vii. App. Iviii. 



Obs. This species by some mistake was placed in the British 

 Collection, and a label of locality in error attached. 

 Hab. United States. 



