Studies of Nortli American Bees 83 



1905. Noiuada {HoJonomada) cebrata Cockerell, Bull. 94, Colorado 

 Exp. Sta., p. 73 and p. 78, ? c?. 



A male collected at Glen, Sioux county, Nebraska, August 12, 

 1906, at flowers of Helianthus petiolaris (H. S. Smith) and a 

 female collected at the same locality, August 20, 1906, by the 

 same coillector on Cleomc serridata, are before the writer. 



Nomada (Holonomada) placida Cresson. 



1863. Nomada placida Cresson, Proc. Ent. Soc. Phil., II, pp. 291-92, 



1903. Holonomada placida Robertson, Can. Ent., XXXV, p. 177, ? d*. 



A series of three females and one male collected at Lincoln, 

 Nebraska, in August and September, is before the writer. 



Nomada (Holonomada) dawsoni n. sp. 



<^. Length 11 mm. Black; a quadrate spot involving most of clypeus 

 medially, suboval spots on sides of clypeus completely separated from the 

 median spot by broad black bands, the squarish supraclypeus, large oblong 

 spots on sides of face and contiguous to orbits, mandibles except tips, a 

 short line behind eyes medially, scape in front and on apical margin behind, 

 and a large spot involving practically all of tegulae, pale yellow ; the collar, 

 a curved spot on mesopleura just beneath tegulae, two tiny spots on meso- 

 scutellum, most of metanotum, elongate oval spots on sides of propodeum, 

 and abdominal maculations, cream color. Scape subglobose, pedicel black, 

 first two joints of flagellum entirely red and next three red beneath; rest 

 of antennae black, joint 3 exceedingly long, almost twice as long as 4, and 

 =4+5. Vertex and mesoscutum shiny, finely and densely punctured, the 

 mesoscutum with five broad longitudinal furrows which are most obvious 

 anteriorly. Mesoscutellum uniformly slightly convex, not at all depressed 

 medially, punctured like mesoscutum. Wings slightly brownish, nervures 

 dark reddish brown, stigma reddish, basal nervure interstitial with trans- 

 verso-medial nervures. Coxae and trochanters black with their apices 

 broadly yellow behind, first four femora black behind with large yellow 

 spots beneath at apex while in front the basal half is black and the apical 

 half reddish, hind femora reddish with the base beneath and behind largely 

 blackish, and a yellow apical spot above, tibiae yellow with large reddish 

 spots within toward apex, the tarsi reddish except for yellowish suffusions 

 on last four basitarsi externally. Abdomen finely and closely punctured, 

 tergite i with large irregular lateral spots, 2 with a narrowly interrupted 

 band, 3-5 with complete bands, all cream color. Venter black with inter- 

 rupted cream color bands on sternites 2-4. Apex entire, rounded, black. 



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