NEW AMERICAN BEES. 267 



and margin of stigma dilute sepia ; third discoidal cell very distinct ; 

 legs black, with the anterior and middle tibiae in front, anterior tarsi 

 and the knees, light yellow ; middle tarsi pale brownish ; abdomen 

 black, with bright yellow markings, consisting of a pair of little spots 

 on first segment, and large oblique marks on sides of second, third, 

 and fourth ; venter dark. Labial palpi comparatively short, the first 

 joint about as long as the other three together. Euns in table of 

 Perdita (Proc. Phila. Acad. 1896) to P. obscurata, from which it differs 

 by the brown nervures and markings of thorax. 



Hah. Florissant, Colorado, at flowers of Lepidium jonesii, 

 Eydberg, July 28th, 1907 ; two females (S. A. Rohwer). At the 

 same time, place, and flowers, Mr. Rohwer took Perdita tortifolice, 

 Ckll., six females, and P. florissantella, Ckll., three females, two 

 males. It has occurred to me that possibly tortifolice may be a 

 mutation of florissantella, although the face-marks are radically 

 different, and there is no sign of anything intermediate, unless 

 a single tortifolia with a little short light stripe on the clypeus 

 can be so regarded. In 1906 the very numerous specimens 

 from Eriogonuni umhellatum were all florissantella ; but in 1907 

 (July 21st-23rd) Mr. Rohwer took from this flower eight floris- 

 santella and one tortifolice. 



Dioxys aurifusca (Titus). 



Chrysopheon aurifuscus, Titus, Canad. Entom. 1901, p. 256 

 (Colorado). 



After studying one of the types of this very distinct species, 

 I am persuaded that Chrysopheon is not more than a subgenus 

 of Dioxys. The species has some resemblance to the Algerian 

 D. rufiventris, Lep. 



Dioxys martii, Ckll. 

 1 have before me two examples taken by Professor C. H. T. 

 Townsend at Las Graces, New Mexico, May 10th and 11th. 

 These show that the venational character cited in the original 

 description (first r. n. joining first s. m.) is not constant; but 

 the species is easily known from D. producta by the rounded, 

 not produced, apex of abdomen. 



Nomada subaccepta, sp. no v. 



(^ . Length a little over 8 mm.; head and thorax black, with 

 quite abundant white hair, which is dense and silky on face ; clypeus, 

 pteral marks, labrum, basal half of mandibles and scape in front all 

 pale yellow ; labrum hairy, and with a small red tubercle ; lateral 

 marks very broad below, but rapidly narrowing to a hue whicii ends 

 at level of antennas ; cheeks entirely black ; a small red spot above 

 each eye ; scape stout, but not swollen ; third joint a little over half 

 as long as fourth ; flagellum stout but normal (not dentate or con- 

 spicuously undulate), red, the basal half black, and the apical more or 

 less dusky, above, though even on the black part there are red sutural 



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