AMERICAN HYMENOPTERA. 79 



sides of the segments black; a yellow band, more or less interrupted on middle 

 on segments 1—6, broader and narrowed towards middle on second segment; 

 venter ferruginous, spotted or banded with yellow. Length .40 inch. 



Hah. — Colorado, (Morrison). Two specimens. This may be only 

 a variety of the preceding species. 



Nomada rivalis.— 'J, .—Black, opaque; head and thorax densely punc- 

 tured, rather thickly clothed with pale pubescence, which is darker on vertex 

 and thorax above; sides of face, lower posterior orbits, clypeus, spot above, 

 labrum, mandibles except tips, scape beneath, collar, two spots on scutellum, 

 tubercles, a more or less large irregular mark on pleura, and tegulse, yellow; 

 antennae black behind, scape robust, flagellura ferruginous beneath, second 

 joint about one-third the length of third; scutellum subbilobate, not promi- 

 nent; wings faintly dusky at tips; legs yellow, tinged with ferruginous, coxse 

 at base, trochanters behind, four posterior femora at base and behind, and spot 

 or stripe on their tibise black; abdomen shining, black, a broad yellow band 

 on all the segments, that on the first deeply notched in the middle anteriorly, 

 the others more or less narrowed in the middle anteriorly, venter yellow. 

 Length .40 inch. 



jjah. — California, (H. Edwards, Behrens). Three specimens. This 

 and the nest species resemble the two preceding species in color and 

 ornamentation, but are distinguished at once by the second joint of 

 the flagellum being much shorter in proportion to the length of the 

 third joint. 



Noinada f'ragiliS.— 'S-— Black, opaque; head and thorax densely punc- 

 tured, rather thickly clothed with pale pubescence; line on sides of face, 

 clypeus, labrum, base of mandibles, line beneath eyes, scape beneath, tuber- 

 cles, sometimes a spot beneath, and occasionally two spots on scutellum, pale 

 yellow ; antennse long, black behind, scape robust, flagellum ferruginous, second 

 joint about one-fourth the length of third; scutellum not prominent; tegulae 

 and legs ferruginous, coxse and all the femora more or less behind black, some- 

 times the posterior femora is almost entirely black as well as their tibite behind 

 and base of tarsi; wings dusky on apical margin; abdomen marked as in the 

 preceding species. Length .30 inch. 



jjul^ — Colorado, (Ridings, Morrison). Three specimens. 



Noiuada cifrina.— 9 .— Black, opaque; head and thorax strongly and 

 densely and face finely punctured; sides of face, clypeus except black dot 

 on each side, spot above, labrum, mandibles except tips, broad posterior orbits, 

 spot beneath lower ocellus, scape beneath, collar, tegulae, spot before, seutellums, 

 spot on each side of metathorax, tubercles and pleura laterally and beneath, 

 all pale lemon-yellow; the pleura has a black dot beneath wings and a short 

 black line behind each anterior coxa; antennae rather long, flagellum fulvous, 

 black at tip, second joint a little shorter than third, both together being longer 

 than scape; scutellum bilobate; wings varied with fuscous; legs pale lemon- 

 yellow, coxae and femora above and behind and a stripe on four posterior tibias 

 behind, black; tips of tarsi fulvous; abdomen pale lemon-yellow, subopaque, 

 base of first, and narrow apical margin of first and second segments black, 



