II. STUDIES OF NORTH AMERICAN BEES 

 III. Families Nomadidae and Stelididae 



BY MYRON HARMON SWENK 



Since the publication of the previous papers on these two fami- 

 lies of bees {antea, XII, pp. 1-113 and XIV, pp. 1-36) the writer 

 has had the opportunity of studying a considerable amount of 

 additional material. Not only the results of our collecting in 

 Nebraska during 1913 and 1914, but also a lot of several hundred 

 specimens received for study from Mr. O. A. Stevens of the 

 North Dakota Agricultural College, and the material in these two 

 families in the University of Kansas collection, received through 

 Mr. H. L. Viereck, has been carefully gone over. As a result, 

 twelve new species of Nomada and one of Stelis have been found 

 and are here described, while there are numerous new facts on 

 distribution, season, flowers visited, etc., which have also been 

 deemed well worthy of publication, and are therefore included. 

 This paper may, therefore, be considered as supplementary to 

 the two previous contributions, bringing the work of the writer 

 on these two families up to date. 



Nomada (Nomada) subnigrocincta n. sp. 



$. Length 7 mm. Coppery red ; supraclypeus, face between and above 

 points of insertion of antennae, oval area including the ocelli, cheeks ex- 

 cept for a narrovif orbital line, prothorax, broad, depressed median line on 

 mesoscutum, depressed sides of mesoscutellum and metanotum, propodeum 

 except sides of enclosure and large contiguous spots thereunder, meta- 

 pleura, broad superior mesopleural sutures, large mesosternal spots, coxae 

 except tips, base and apical margin of tergite i, black. Pubescence of head 

 and thora:ji wholly white, copious, especially on labrum, face, cheeks, pleura 

 and propodeum. Antennal joints 1-3 dark testaceous, following joints 

 reddish fuscous becoming blackish above, joint 3 about two-thirds as long 

 as 4. Mesoscutellum strongly bigibbous. Tegulae large, shiny, coppery 

 red. Wings darkened along apical margin, nervures brownish fuscous, 



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