I04 Myron Harmon Szvenk 



scutellum, and flagellum beneath apically, red; abdoi;ninal bands 

 interrupted on i but continuous on 2-6; ii mm erigeronis. 



Nomada (Centrias) erigeronis Robertson. 



1897. A'oinada erigeronis Robertson, Trans. Acad. Sci. St. Louis, VII, 



pp. 341-42, ?. 

 1903. Centrias erigeronis Robertson, Can. Ent., XXXV, pp. 17^77^ 



1903. Nomada erigeronis Cockerell, Proc. Acad. Nat. Sci. Phil., p. 

 588, ?. 



Cockerell (/. c.) gives descriptive notes on a female from 

 Nebraska in the collection of the Philadelphia Academy, no 

 further data regarding this specimen being known. A series of 

 five females and one male of this little known bee was collected 

 by L. Bruner and the writer in the Pine Ridge of Dawes county 

 northeast of Crawford, Nebraska, July 7, 1910, at flowers of 

 Brauneria pallida. A female collected on the same flower at Blue 

 Rapids, Kansas, July 3, 1907, by O. A. Stevens (No. 1447) is 

 before the writer; also a single male collected in Warbonnet 

 canyon, Sioux county, Nebraska, June 29, 1901, on Campanula 

 rotundifolia, by J. C. Crawford, and a third Nebraska male col- 

 lected at Weeping Water, July 20, 1906, by H. S. Smith. 



Subgenus Micronomada Cockerell, 1902 



KEY TO THE NEBRASKA SPECIES 



Females 



Mesoscutum with the punctures very dense, more or less subcancellate. ..i 



Mesoscutum with the punctures well separated, not subcancellate 5 



I. Propodeum with yellow spots 2 



I. Propodeum without yellow spots 3 



2. Clypeus wholly black ; 7.5-9 mm modesta 



2. Clypeus wholly or largely red; 7-9 mm modesta vegana 



3. Yellow band on tergite 2 broad laterally but gradually much nar- 

 rowed medially; abdominal sternites 3 and 4 with narrowly 



interrupted pale yellow lines ; mm texana 



3. Yellow band on tergite 2 subuniformly broad, merely sharply notched 



medially on anterior margin; abdominal sternites all black.... 4 



4. Punctures of mesoscutum very coarse and close, mostly subcancellate 



and causing a rugose surface ; flagellum dusky above ; supra- 



clypeal area black ; lateral face marks narrowly linear, yellow 



104 



