THE CANADIAN ENTOMOLOGIST. 277 



3. Hind metatarsus about twice as long as broad, with a posterior lobe ; 



clypeus broadly sulcate ; labrum striate ; front femur with long 

 white hair; thorax above mixed with black ; 9-10 mm. . . latitarsis. 

 Hind metatarsus about three times as long as broad ; 



8-9 mm Willistonii. 



4. Joint 4 shorter than 2-3, not much longer than 3 ; labrum plane, or 



with a faint fovea ; ventral segments 2-5 strongly bearded laterally; 

 malar space short ; thorax above ochraceous ; cell IHr, short, 



strongly narrowed above . sestivalis. 



Joint 4 about as long as 2-3 5. 



5. Malar space at least about one-half as long as wide 8. 



Malar space not more than one-third as long as wide 6. 



6. Postscutel with transverse series of subquadrate pits ; 9 mm. . .nudus. 

 Postscutel densely punctured and pubescent 7. 



7. Mesonotum rather evenly punctured; prothoracic spines indistinct; 



pubescence ochraceous ; 8 mm Americanus. 



Mesonotum with two densely punctured submedian streaks ; pro- 

 thoracic spines distinct ; pubescence griseous or whitish, usually 

 mixed with black on vertex and thorax above ; 8-9 mm. .armatus. 



8. Metathorax with triangular rugose enclosure ; maler space as long as 



wide; pubescence mixed wiih black above; 9-10 mm. .compactus. 

 Metathorax truncate ; with transverse series of subquadrate pits . . .9. 



9. Pubescence of scutel mixed with black ; malar space shorter than 



wide; 10-12 mm insequalis. 



Pubescence of scutel not mixed with black ; 7-8 mm 10. 



10, Punctures of mesonotum and scutel about equal in size ; malar space 



shorter than wide ; pubescence rather dense, ochraceous . .eulophi. 

 Punctures of mesonotum rather fine and sparse, of scutel very coarse; 



malar space nearly as long as wide ; pubescence thin, 



griseous productus. 



Megachile strophostylis, sp. nov., ^ .—Black ; closely punctured and 

 hardly shining ; pubescence rather long and pale ; short, thin and black 

 on vertex, mesonotum, scutel, discs of segments 2-5, and base of 6; 

 lateral ocelli about equally distant from vertex and nearest eye; mandibles 



