Studies of North American Bees 25 



of tergite 4 black like those on 1-3, lack of yellow spots on sides 

 of abdominal tergites 2 and 3 and on disk of 4, and the usual 

 presence of a yellowish suffusion or color on the sides and lower 

 corners of the face and on the labrum. From N. nigrocincta 

 Smith, it differs in much the same color characters (1. e., the lack 

 of black lines on mesoscutum and propodeum, black spots on 

 clypeus, about ocelli and on flagellum above and black areas on 

 base of abdomen and bases of femora) and also in the practically 

 bare sides of the propodeum. All three species fly in June. A^. 

 pidsatillae Ckll. is also related, but an autotype in the U. S. 

 National Museum differs in the longer third antennal joint, much 

 darker red color with the abdominal bands less intensely black, 

 more dusky, the complete lack of yellow on the face, labrum and 

 abdomen, the face and scape with blackish bristles, and a fronto- 

 ocellar spot, mesoscutal line, sides and base of propodeum, and 

 whole of metanotum and metapleura, black; also, it flies earlier 

 in the season than the above species. 



Nomada (Nomada) bilobata 11. sp. 



$. Length 7 mm. Color dark red, with the mandible tips, antennae 

 above, area from antennal bases to and including ocelli, cheeks behind, 

 pronotum except collar, median line on mesoscutum, mesoscutal sutures, 

 metapleura, propodeum except two large red lateral spots which involve 

 most of the enclosure, depressed areas at extreme sides of mesoscutellum 

 and metanotum, the coxae and bases of femora behind, apex of posterior 

 tibiae behind and all of posterior tarsi, and a small trident-shaped mark 

 at the base of the abdomen, black or blackish. Antennae beneath bright 

 red on the first three joints, darker red on the following joints, joint .3 

 about three-fourths as long as 4. Clypeus strongly and densely punctured, 

 the vertex and mesoscutum with very coarse, strong punctures. Meso- 

 scutellum crested and deeply bilobed. Pubescence of vertex and mesono- 

 tum very short, sparse and pale ochreous, that on cheeks and pleura 

 similarly short and thin but of a white color, the sides of the propodeum 

 abruptly with long, dense, erect, silvery hair, the legs with fine appressed 

 silvery pile, the hair on the inner sides of hind basitarsi pale. Tibial 

 spurs pale and not distinctly pectinate. Tubercles and tegulae paler, 

 almost coppery red. Wings heavily darkened on a broad apical band and 

 in the marginal, submarginals and discoidals among the cells, a clear 

 spot beyond submarginals. Third submarginal cell much narrowed above, 

 and the basal nervure very slightly basad of transverso-medial nervure. 

 Abdomen dark coppery red, concolorous with the tubercles and tegulae 



25 



