68 S. W. WILLISTON, M. D. 



silvery- white. Hypopygium deep red, of moderate size, thinly black and white 

 pilose. The pile of the basal sfgments is not abundant, white, on the venter below 

 with loose tufts. Legs black, with white pile and white and black macrochfetse ; 

 front and middle tibiae, except the tip, and hind tibiae, except the distal third or 

 half, red or yellow. Front and middle tarsi deep red, hind tarsi usually blackish. 

 "Wings hj'aline; anterior cross-vein at the middle, furcation of the third vein a 

 very little beyond the distal end of the discal cell. 



9 • Second abdominal segment usually with a brownish spot, sometimes with 

 a blackish spot on each side; the remaining segments each with a pair of large 

 quadrate spots, rather narrowly separate. 



One male from Wasliington Territory, five males from California, one 

 male and two females from Western Kansas, ten males and eight females 

 from Arizona and two females from Connecticut. 



F.rax staniiueus n. sp. 



% .—Length 15-17 mm. Face, beard and antenna; wliolly with yellowish white 

 hair or pile, the ocellar and occipito-orbital bristles black. Face densely covered 

 with yellowish white pollen. Dorsum of thorax black, moderately shining, not 

 thickly covered with grayish pollen, the usual stripes narrowly separated, the 

 short sparse pile and the bristles black. Pleurae rather thickly light pollinose, the 

 sparse pile wholly white. Abdomen black, first two segments rather thickly 

 gray pollinose, leaving a rather broad, more black band on the second; third to 

 seventh segments on the dorsum silvery pollinose and rather thickly clothed with 

 silvery-white pile, which is parted in the middle and directed outwards; this 

 white pile is on the second segment also, but less abundantly. Hypopygium elon- 

 gate, shining black, with light yellow pile. Legs wholly black, with yellowish 

 white pile and black and white bristles. Wings short, hyaline ; anterior cross- 

 vein near the middle of the discal cell; second sub-marginal cell very long, the 

 furcation of the third vein takes place only a little beyond the anterior cross- vein. 



Two specimens, Montana (Professor Comstock). 



£rax n. sp. 



%• — Is very similar to stamineus, hut is apparently different. The tibite and 

 tarsi are all yellowish red except the tips of the former. The hypopygium is dis- 

 tinctly smaller, and the second sub-marginal cell is shorter. 



AVasliington Territory. One specimen. 



An additional specimen from Arizona agrees with the preceding ex- 

 cept that the second sub-marginal cell is longer than in stamineus. Until 

 further material is examined it will be unwise to give them a name. 



Eras siiuilis n. sp. 



9 . — Length 24 mm. A single specimen with the last seems to be diflTerent, in 

 that the head is provided with black bristles, the bristles of the thorax wholly 

 black and the furcation of the thii-d vein takes place opposite the end of the discal 

 cell and not a considerable distance before it, as in the preceding. The abdomen 

 is thickly gray pollinose with a series of black triangles in the middle of the seg- 

 ments, with the base in front and becoming successively less in size; the pile of 

 the legs is short and white, with the bristles black. 



Hab. — Arizona. 



