70 Mr. T. D. A. CockcvcW— Descriptions and 



of base and a linear one in the midflle ; apical band of 

 tomentum on fifth segment narrow; pygidial plate broa'ily 

 rounded ; venter red, without markings. 



Hub. Boulder, Colora-^lo, at flowers of Pahalilla hirsu- 

 tis.nma, h\n'\\ 20, 190f) [Cocherell]. 



In the table of Rocky Mountain species (Bull. 94, Colo. 

 Exp. Sta.) this runs to 6S, and runs out because the abdomen 

 has no yellow spots. From N. Packardiella it differs by the 

 much broader abdomen, without yellow spots or distinct 

 black bands, the golden pile on the entirely red hind til)i;e, 

 &c. From N. Clurkii it differs by its smaller size and the 

 details of the coloration of the abdomen, but the two are 

 closely allied. From A^. latifrons it differs by the broad 

 abdomen &c. It is also related to N. valida. 



There is quite a strong superficial resemblance (as seen 

 •without a lens) to A^. poh/acantha, Perez, from Barbary, but 

 that species has the b. n. meeting t.-m., the raesothorax 

 black, &c. 



Nomada undulaticoniis, sp. n. 



^. — Length about 8 mm. 



Black, lemon-yellow, and ferruginous ; mandibles simple ; 

 anterior coxae pointed at apex, but not spined ; head coarsely 

 sculptured, black, with the labrum, base of mandibles, clypeus 

 except u])per lateral margins, and lateral face-marks (ending 

 very narrowly on orbital margins below level of antenna), 

 all yellow ; facial quadrangle longer than broad ; pubescence 

 of head and thorax rather abundant, pallid, with an ochreous 

 tint, face with appressed silky hair; scape not greatly 

 swollen, yellow in front ; flagellum ycllowisli ferruginous 

 beneath, above black about as far as the eighth (antennal) 

 joint ; third antennal joint about as long as the fouith, 

 apical joint pointed ; joints G to 9 strongly undulate beneath, 

 or, one might say, tubereulate ; mesothorax entirely black, 

 very coarsely and conHuently rugoso-punetate ; tubercles red ; 

 a small red maik on anterior i)art of pleura ; scutcllum 

 strongly big.bbose (mammiform), the gibbosities red ; mcia- 

 thorax entiiely bUu k, rugoso-plicate basally ; teguhe red, 

 dullish, cloSL'ly punctured. \Vings strongly dusky at apex, 

 stigma ferruginous, ncrvurcs fuscous; second s.m. rather 

 narrow; b. n. going only just basad of the oblique t.-m. 

 Legs red, coxie largely black, middle femora with the basal 

 two fifths behind l)lack ; hind femora mostly suflused with 

 black on both sides. Abdomen broad, convex, dark ml, 



