Till-: CA.NAUIAX ENTOMOLOGIST. 161 



cell ; the abdomen and legs are about the same, except that the light hair 

 of the abdomen has not any distinct tendency to form patches, and is 

 reduced almost to nothing on the third segment. Perhaps this should be 

 referred to Moninnet/ia, if that is a valid genus ; but I am not quite sure 

 whether it is really a close ally of J/, argeniifrons or an example of 

 "convergent evolution." O. frigida, Sm., seems to be allied. 



Hab. — Boulder, Colo., June 27, 1905. (W. V. Cockerell. ) 



Osmia JVovom^xicana, Ckll., was taken at Roulder, Colo., June 17, 

 1905. (W. P. Cockerell.) It is new to Colorado. 



Nomada oniithica, n. sp. — ^. Length, 8 mm., or a little more; 

 black and lemon-yellow, with some led on legs ; belongs to the subgenus 

 Xanthidiutn. Head and thorax densely and coarsely rugoso-[)unctale ; 

 eyes sage-green ; head broad : mandibles (except apically), labrum, 

 clypeus, supraclypeal mark (which is. large, and broader than long) and 

 lateral face-marks all yellow, except that there is a very small black spot 

 on each side of clypeus, at the suture ; labrum with a very small apical 

 tubercle ; face little hairy, but the supraclypeal area and upper part of 

 clypeus are covered with ai)pressed white hair ; lateral face- marks tri- 

 angular, following clypeus to the top, but ending bluntly and a little away 

 from the orbital margin, a short distance below level of antennae : lower 

 orbital margin narrowly yellow, the stripe going a short distance up the 

 posterior margin ; scape swollen, lemon-yellow, black behind : flagellum 

 thick, red beneath and laterally, but black above, the black more exten- 

 sive on the apical joints ; no sign of denticulation ; third antennal joint 

 about half as long as fourth ; mesothorax coarsely rugoso-punctate, 

 entirely black ; upper border of prothorax, tubercles, tegulae, large mark 

 on pleura (having the shape of a bird's head and neck, the tip of the bill 

 almost touching the tubercle), scutellum, except margins, and a short band 

 on i)ostscutellum, all yellow : scutellum swollen and bigibbous : meta- 

 thorax black, with a smili yellow spot on each side near the lower end; 

 anterior coxte without spines ; legs yellow, suffused with ferruginous 

 basally, with black on the coxae, trochanters, and posterior femora and 

 tibite behind ; wings dusky at apex, stigma ferruginous, nervures more 

 fuscous ; basal nervure meeting transverse-medial ; second submarginal 

 cell twice as broad as third above ; abdomen very minutely punctured, 

 and with six broad yellow bands, the intervals between the first four black, 

 but the hind margins of the fourth and fifth segments reddish ; apical 

 segment black basally ; apical plate notched ; ventral segments nearly all 



