NO. 1852. BEES OF THE GENUS NOMADA—COCEERELL. 241 



NOMADA (GNATHIAS) BELLA Cresson. 



Females: Bear Creek, Colorado, July 7, 1897 (collector unknown); 

 Colorado (Baker 884). 



NOMADA (GNATHIAS) CUSTERIANA, new species. 



Male. — Length a little over 6 mm. ; head and thorax black, rugoso- 

 punctate, with long white hair, dense and silvery on face; head trans- 

 versely oval; eyes pale greenish-grey, their distance below at least 

 as great as the length of an eye; mandibles ferruginous, strongly 

 bidentate at end; the Hnear malar space also ferruginous, but tegu- 

 ment of labrum, clypeus, and all the rest of head entirely black; an- 

 tennae reaching base of metathorax; scape black; flagellum bright 

 ferruginous, the upper surface black above and fiattish on the basal 

 half, on the apical half not quite so dark, though strongly infuscated; 

 third antennal joint much shorter than fourth, fourth about as long 

 as last; thorax entirely black; tegulje large, punctured, rufopiceous; 

 stigma and nervures ferruginous; b. n. going only a very little basad 

 of t. m. (unusual venation for a Gnathias) ; second s. m. broad, receiv- 

 ing first r. n. about middle; third s. m. extremely broad, but nar- 

 rowed to about a fifth of its length above; legs black basally, with 

 the knees broadly, the tibise and tarsi chestnut red; anterior and mid- 

 dle tibise with a dusky suffused patch on outer side; abdomen dark 

 red. The first segment black at base, the black gradually melting 

 into the red; segments 2 to 6 with cream-colored bands, on 2 very 

 broad, interrupted by red in middle, on 3 narrower, also interrupted 

 by red, on 4 with a linear median interruption, but a very broad one 

 on each side, on 5 and 6 continuous in the middle, but failing laterally; 

 apical plate long, notched; venter chestnut red, nude, except for a 

 large apical tuft of hair. 



Hahitat.— West Cliff, Colorado (T. D. A. Cockerell). Labeled by 

 Doctor Ashmead Nomada pacata Cresson, a species to which it is not 

 allied, although the markings of the abdomen are very like those of 

 pacata. Among the small species of Gnathias it will be readily known 

 by its wholly dark face and the venation. 



Type.— Cat. No. 14023, U.S.N.M. 



In the Transactions of the American Entomological Society,* 

 N. parata Cresson is recorded from West Chff, but not pacata. I am 

 practically certain that N. custeriana is one of the specimens cap- 

 tured May 19, 1889, of which I have a note that the size was small 

 and the thorax black. This was determined at the time by Doctor 

 Ashmead as N. parata, and was the basis of the record just cited. 



The specimens labeled ''West Cliff, Col." in the U. S. National 

 Museum, from the Ashmead collection, are all of my collecting, 

 though this is not stated on the labels. So far as the aculeate Hymen- 



iVol. 20, p. 339. 



94428°— Proc.N.M.vol.41— 11 16 



