NAMES APPLIED TO BEES OF THE GENUS OSmA, 

 FOUND IN NORTH AIMERICA. 



By T. D. A. COCKERELL, 

 Of (he University of Colorado, Boulder. 



This list is prepared in the same manner as the paper on the genus 

 Nomada, which appeared in these Proceedings, vol. 41, pp. 225-243. 

 Our knowledge of Osmia in America has very greatly increased in 

 recent years, and in the absence of a catalogue it has been difficult 

 to keep the numerous species in mind. Friese's revision of the 

 Megachilidse of the world, published in Das Tierreich, November, 

 1911, includes the Nearctic Osmise, but unfortunately the manu- 

 script was prepared ten years ago, and has not been brought up to 

 date; it thus falls very far short of representing our present knowl- 

 edge, although very valuable as fas as it goes. 



According to Titus,^ the type of Osmia Panzer is 0. rnfa (Linnseus). 

 The only American species which he considers strictly congeneric with 

 rufa are 0. lignaria and 0. propinqua. The genus is here interpreted 

 in a broader sense, in accordance with the more usual custom. Rob- 

 ertson divides Osmia into a number of genera, but restricts the name 

 Osmia to such species as 0. hrevis, pumila, cohaltina, and atriventris, 

 applying the name Ceratosmia (Thomson 1872) to the Osmia, s. str. of 

 Titus. Ashmead, however, recognized Amhlys Klug (type, hicomis, 

 which =rufa) as a genus distinct from Ceratosmia: he considered 

 Helicosmia (the group of 0. aurvlenta, hicolor,^ etc.) to be identical 

 with Amhlys. 



The genus Osmia is very rich in species throughout the temperate 

 portions of the Northern Hemisphere. The American forms are 

 mostly blue or green, some very brilliant, while those of Europe aver- 

 age much darker, with a much larger proportion of actually black 



» Journ. N. Y. Ent. Soc, 1904, p. 26. 



» Apis bicolor Schrank (=Osmia bicolor) and Apis bicolor Fabricius ( = ilegachile bicolor) were both pub- 

 lished in 1781; I do not know which has priority. Should Fabricius have priority, then Osmia bicolor 

 would become Osmia rustica (Apis rtutica Fourcroy 1785), which would make O. rustica Cresson a homonym. 



Proceedings U. S. National Museum, Vol. 42— No. 1897. 



