1938] 
Genus Macropis 
133 
A REVIEW OF THE AMERICAN BEES OF THE GENUS 
MACROPIS (HYMEN., APOIDEA) 
By Charles D. Michener 
University of California, Berkeley, Calif. 
Since the genus Macropis has not previously been re- 
corded in America west of eastern Colorado, it is of interest 
to find M. morcei, the most widely distributed of our species, 
in Montana, and a new form of M. steironematis in Washing- 
ton State, an extension of the known range of the genus by 
well over one thousand miles. 
A comparison of our species with the descriptions and 
figures of Old World forms shows that the North American 
species belong to Macropis s.str., not to the subgenus Para- 
macropis 1 . Indeed the genitalia and sternites of our species 
agree in all essential points with the figures of M. labiata 
given by Saunders 2 . There are, however, certain differences, 
both in the genitalia and in the sternites. In M. morcei and 
ciliata the lateral projections of the eighth sternite, slender 
in labiata , are mere angles, while in M. steironematis opaca, 
described below, they are broad, rather truncated anteriorly, 
and about as long as in labiata. In M. morcei the genitalia 
are very similar to those of M. ciliata but differ in the some- 
what shorter outer ramus of the stylus. I have not been able 
to study the genitalia of M. patellata or typical M. steirone- 
matis. 
If M. longilinguis Provancher 3 , described from the female, 
proves to be true Macropis , it is probably a synonym of ciliata 
or patellata. Scrapter andrenoides Smith 4 , which was re- 
ferred to Macropis by Dalle Torre is placed in Pseudopanur- 
gus by Cockerell 5 . 
iPopov and Guiglia, 1936, Ann. Mus. Civ. Storia Nat. Genova, 59:287. 
Popov, 1936, Proc. Royal Ent. Soc. London (B) 5:78. 
2 Saunders, 1882, Trans. Ent. Soc. London, pi. 10. 
3 Provancher, 1888, Add. Faun. Ent. Can. Hym., p. 424. 
4 Smith, 1853, Cat. Hym. Brit. Mus., 1:121. 
5 Cockerell, 1904, Can. Ent., 36:303. 
