ART. 20 REVlSIOlSr OF THE GENUS WINTHEMIA EEINHARD 11 



Wings hyaline ; third vein with one hair at base ; fourth vein with 

 an oblique bend, beyond straight to costa; first posterior cell open 

 well before wing tip. 



Female. — Front 0.287 and 0.327 of the head width in two speci- 

 mens, more densely pollinose than in male; the usual two pairs of 

 orbitals present ; uppermost three or four f rontals reclinate ; ocellars 

 present but poorly developed ; outer verticals about one-half as long 

 as inner pair; palpi thickened apically; claws and pulvilli short. 



Length, 6 to 8 mm. 



Type. — Female, U.S.N.M. No. 6222, from Los Angeles County, 

 Calif. 



Redescribed from the following, all in the United States National 

 Museum: 1 female. Dripping Springs, N. Mex. (T. D. A. Cockerell) ; 

 1 female (type), Los Angeles County, Calif., July (D. W. Coquil- 

 lett) ; and 1 male. Summit, Mount Lowe, Calif., July 4, 1917 (J. M. 

 Aldrich). 



The species varies in the development of ocellar bristles. The 

 type female has a weak or hairlike pair of ocellars; in the second 

 female they are hardly distinguishable from the adjacent hairs, while 

 the single male specimen shows none at all. 



(2) WINTHEMIA TIBIALIS, new species 



Abdomen densely gray pollinose, the hairs long and erect on 

 dorsum of intermediate segments; tibiae yellow, the middle pair 

 with two stout bristles on outer front side near middle; thoracic 

 stripes indistinct. 



Male. — Front (at vertex) 0.316 of the head width in the one speci- 

 men, widening rather slowly to base of antennae ; paraf rontals gray 

 pollinose, covered with long black hairs; median stripe reddish 

 brown, hardly narrowed upward, at antennae almost as wide as one 

 paraf rontal; verticals one pair (inner) developed; orbitals none; 

 ocellars large, directed forward and outward; frontal rows strongly 

 divergent beneath antennae, extending to base of third joint, the 

 uppermost bristles not reduced in size, reclinate; sides of face gray 

 pollinose, narrowed downward, bearing a few rather inconspicuous 

 hairs, which extend from the lower frontals to about the middle 

 along the inner margins ; antennae black, almost reaching oral mar- 

 gin, third joint nearly four times the length of second; arista of 

 moderate length, thickened on basal third, penultimate joint short; 

 vibrissae on oral margin, the ridges with a few bristles above ; palpi 

 yellow; cheeks gray pollinose, clothed with long fine black hairs, 

 in profile about one-sixth the eye height. 



Thorax black, gray pollinose, with a rather noticeable yellow 

 spot above wing base, which extends backward to include the pos- 



