Studies of North American Bees 33 



Basal nervure interstitial with the transverso-medial distinctly on the 

 basad side, second submarginal cell little narrowed above, broader than 

 tliird. Tegulae yellowish red. Cheeks, pleura, mesonotum, and sides of 

 propodeum with erect, rather long and thin, grayish white hair intermixed 

 with prominent black bristles on mesonotum and mesopleura, the face, 

 scape, labrum, legs and sides of abdominal tergites 3-6, with disk of 5 

 and apex of sternite 5, bearing abundant, conspicuous, long, black 

 bristles. 



Type. — Sioux county, Nebraska, May (L. Eruner), $. 



This form is a member of the calif orniae-latifrons group, char- 

 acterized by the broad head, usually black bristles on scape, joint 

 3 of antennae nearly as long as 4, abdomen without yellow spots, 

 moderate punctures of mesoscutum, etc. It is closest to N . lati- 

 frons Ckll., described from two female specimens from the Santa 

 Cruz mountains of California, and agrees with that species in 

 the antenna! structure, the closely and coarsely punctured clypeus, 

 the golden hair on inner side of hind basitarsi, the pale simple 

 tibial spurs, etc. It is separable from the type of latifrons (U. 

 S. National Museum, Cat. No. 13155J by the long, abundant and 

 conspicuous black bristles on the scape, face, labrum, legs and 

 sides of abdominal tergites 3-6 (in latifrons the scape, sides of 

 vertex and upper face have a few short, inconspicuous black 

 bristles only, while the legs have the hair pale with only a few 

 inconspicuous black bristles on the hind tibiae and only tergites 

 5 and 6 have black bristles j, the pygidial area broadly rounded, 

 glabrous, coarsely and closely striate-punctate except on the ex- 

 treme margins along the raised bordering rim (in latifrons the 

 pygidial area is apically slightly truncate and provided with 

 closely set pale appressed hair), the apex of the hind tibiae with 

 about three short straight setae (about four long curved ones in 

 latifrons,) the apical margin of tergite 5 with a narrow thin band 

 of dense whitish tomentum (a broad pale floccus in latifrons), 

 the less extensively black hind femora (much over half the 

 posterior face is black in latifrons), and the more extensively 

 black sides of propodeum and broad union of the frontal and 

 ocellar black patches (these isolated or connected by two bands 

 enclosing a red spot in latifrons). From N. calif orniae Ckll., it 

 differs in possessing a large black facial patch, more black on 



33 



