26 Myron Harmon Szvenk 



and Achillea millefolium, collected in 1913 and 1914, is before 

 me; of the males six have red on the mesoscutum (dacotana) 

 and one has this sclerite wholly black (articulata) . Also before 

 me are four females and two males from Fairmont, Nebraska 

 (G. W. Deming), June 17 and 20, 1914, of which one male is 

 dacotana and one articulata. A male from Lincoln, June 10, 

 1914 (G. W. Deming), is articulata and a male from Red Cloud, 

 Nebraska, June 18, 1913, on Callirhoe inz'olncrata ('R. W. Daw- 

 son), is dacotana. This material, together with that previously 

 reported upon (antea, XII, pp. 101-102) shows dacotana to be 

 merely a color variation and only very feebly correlated with 

 geographic range. 



The type of Nomada hilohata Swenk is a female without de- 

 veloped coxal spines and therefore, strictly speaking, can scarcely 

 be a Nomadula. Yet its general characters are indistinguishable 

 from those of A^^. articulata, and I have concluded it is simply an 

 abnormal specimen of articulata (probably form dacotana) ; cer- 

 tainly it does not go with the male I previously placed with it 

 {antca, XII, pp. 25-27). The six female paratypes of hilohata 

 from North Dakota (Fargo, Jamestown and Valley City) are 

 certainly A'', articulata, and have the coxae obviously spined. N. 

 hilohata 5 therefore becomes a synonym of N . articulata dacotana, 

 but the name hilohata can be retained for the male described 

 under it. 



Since publishing my former paper I have studied a large 

 additional series (83 5$, 41 J^J*) of N. articulata from North 

 Dakota, submitted for study by Mr. O. A. Stevens. Of the males 

 38 are form dacotana and 3 form articulata. I find no important 

 variations not already noted for the species. The series was 

 collected mostly in 1913 and 1914, at Lisbon, Fargo, Monongo, 

 Lucca and Kathryn, North Dakota, June 5 to July 20, at flowers 

 of Zisia aurea, Melilotus officinalis. Ranunculus macounii, Bras- 

 sica nigra, Brassica campestris, Erigeron philadelphicus, Lactuca 

 pulchella, Amorpha canescens, Meriolix serrulata and Leontodon 

 taraxacum ; mostly, however at the Erigeron philadelphicus. 



Two males from Southern Pines, North Carolina, April 14 and 



180 



