1926 ] 
On the Megachile of South Dakota 
163 
in M. pugnata pomonce Ckll., but the pubescence is white, not 
ochraceous. 
Megachile mucida Cress. 
2 9 9: Spearfish (no date) and Harney Peak (July 22). 
Megachile montivaga Cress. 
1 9 : Custer (no date). 
Megachile integra Cress. 
1 d : Elk Point (Aug. 10, 1924, H. C. Severin). 
Megachile vidua Sm. 
8 cfd 1 , 2 9 9: Hot Springs, Custer, Whitewood, Lead and 
Harney Peak (July). 
Megachile pruina Sm. 
3 d cP , 4 9 9 : Interior, Ft. Pierre, Martin, and Nowlin Co. 
(Aug. and Sept.) 
Megachile melanophoea Sm. 
7 d d : Harney Peak, Lead and Custer (July). 
Megachile relativa Cress. 
2 c?d% 4 9 9: Harney Peak (July), Custer and Hot 
Springs. 
Megachile infragilis Cress. 
5 9 9: Brookings (June and Aug.) and Newell (June). 
This is very close to the preceeding species, the two being sep- 
arable as follows: 
Segment 6 of 9 with appressed golden pubescence and 
erect light hair, sometimes with a few dark basal hairs, 
margin of clypeus indistinctly emarginate medially; 
clypeal margin in d with a distinct and quite strong 
median tubercle relativa 
Segment 6 of 9 with pubescence all dark and with 
numerous erect black hairs, clypeal margin not at all 
emarginate but slightly and broadly produced medially; 
clypeal margin in d somewhat angulate medially, but 
not tuberculate infragilis 
Chelostomoides ruflmanus Rob. 
1 d : Spearfish (July 28, 1924). 
