88 Myron Harmon Szvenk 



Allotype. — Fargo, North Dakota, July 31, 1910, on Lactuca 

 pulchella (O. A. Stevens, No. 2023), 5. 



Nomada (Holonomada) dacotensis n. sp. 



?. Length 8 mm. Black; a subtriangular spot on each side of the 

 clypeus, a line on collar, the tubercles, sometimes a small spot on tegulae, 

 coalesced spots on mesoscutellum forming a diamond-shaped patch, a spot 

 at base and an elongate cuneate mark on the outer face of the hind tibiae, 

 large cuneate marks on sides of abdominal tergites 2 and 3, complete bands 

 on tergites 4 and 5 which are sometimes emarginate on anterior margin 

 laterally, very pale yellowish or cream color. Head and thorax everywhere 

 very densely punctured, coarsely so on thorax, vertex and face, more finely 

 so on clypeus and cheeks, devoid of hair. Antennae black, rather strongly 

 suffused with dark red toward base of flagellum beneath, especially on 

 antennal joint 3 which is very distinctly longer than 4 or following joints 

 except 12, the median joints distinctly broader than long. Legs black, the 

 anterior femora and tibiae in front and whole of tarsi, middle knees and 

 line on tibiae in front, red, yellow spots as mentioned. Tegulae shining, 

 rufo-piceous. Wings slightly darkened basally, heavily darkened on a 

 broad apical margin and in marginal cell, clearer in an area beyond third 

 transverse cubital and second recurrent nervure, nervures and stigma 

 black, basal nervure interstitial with transverso-medial on the basad side. 

 Abdomen minutely punctured, tergum black except for the pale macula- 

 tions mentioned, venter sometimes with pale bands on sternites 3 and 4 

 which are usually interrupted medially, and pale spots on sides of sternite 

 5. 



Type. — Fargo, North Dakota, August 17, 191 1, on Grindelia 

 squarrosa (O. A. Stevens, No. 2803), $. 



Paratype. — Type locaHty, August 14, 191 1, on Melilotus alba 

 (O. A. Stevens, No. 2604), $. 



This species is alHed to A''. aqnUarum Ckll., but differs in con- 

 siderably larger size and more robust form, presence of yellow 

 spots on the sides of the face and a yellow line on the collar, 

 yellow marks on the hind tibiae, etc. The writer at first thought 

 this to be the unknown female of A^. beulaJiensis Ckll., which was 

 collected in company with the type, but the larger size, pale 

 maculations, etc., argue against this ; moreover, benlahensis is 

 apparently a Nomada sens. str. It is closely related to N. mutans 

 Ckll., from Washington State, but differs in the wholly black 

 clypeus, labrum, mandibles, posterior orbits, mesopleura and 

 mesoscutum, the greatly reduced lateral face marks and pale 



88 



