588 PROCEEDINGS OF THE ACADEMY OF [Aug., 



densely punctured, with a blackish median band ; scutellum prominent, 

 apparently yellow, with very large punctures ; enclosure of metathorax 

 jet black, strongly contrasting with surrounding parts, having a well- 

 defined little area of fine ridges on each side ; tegulae large, ferruginous, 

 punctured; wings dusky, especially the apical margin very broadly; 

 nervures brown; stigma small, ferruginous; second submarginal cell 

 very broad, receiving the recurrent nervure less than a third of its 

 width from the end; third submarginal cell rather narrow, with its 

 outer side curved rather than bent; legs bright ferruginous. 

 The insect is evidently a Holonomada. 



Nomada excellens, Ckll., var. a. 



9 . — Lateral black stripes on mesothorax evanescent; red spots on 

 metathorax larger; black spots at base of first al^dominal segment 

 evanescent. 



Hab. — Nevada (no other particulars known) ; one in Coll. of Acad. 

 Nat. Sci. Phila. 

 Nomada erigeronis, Rob. 



9 . — Length about 11 mm., with a very broad abdomen. Has sim- 

 ple mandibles and large spines on front coxas, and belongs to Centrias, 

 of which it is the type species. The stigma is very small; second sub- 

 marginal cell broad; basal nervure only just basad of transverso-medial. 

 The specimen before me is from Nebraska (no other particulars known) , 

 in Coll. of Acad. Nat. Sci. Phila., where (as Mr. Viereck tells me) 

 it was mixed with N. belfragei. 

 Nomada latifrons, Ckll., var. o. 



9 . — Length about 9 mm. ; the black ocellar area completely sep- 

 arated by red from the black area just above the antennse. 



Hab. — Nevada (no other particulars known); one in Coll. of Acad. 

 Nat. Sci. Phila. 



Nomada vinnula, Cress. 



A new locality is Corvallis, Ore., June 1 to 10, several females 

 (Cordley). The female is very near N. echvardsii, but has a broader 

 face, pleura with only a yellow triangular mark, and mesothorax 

 wholly black. I do not know how to separate the male from edwardsii, 

 or it may be that all my males are edwardsii. Prof. Cordley took 

 female edwardsii at Corvallis on April 3 and May 11. 

 Nomada nigrocincta, Smith. 



Prof. Cordley took the female at Corvallis, Ore., June 3. The man- 

 dibles are simple, and the abdomen has distinct black bands. There 

 is some yellow at the lower corners of face, and small inconspicuous 



