576 PROCEEDINGS OF THE ACADEMY OF [A-Ug., 



first two pairs having a red spot on or near the hind margin, the third 

 (on third segment) ahnost divided into two by an anterior intrusion 

 of the red; fourth and fifth segments with broad cream-colored bands, 

 deeply notched at the sides anteriorly, the notches rounded; venter 

 red, with six rib-shaped (curved) whitish marks. 



Hah.~"So. Cal.," one in Coll. Acad. Nat. Sciences Phila. Named 

 after Dr. A. Davidson, who has discovered many Calif ornian bees. The 

 general appearance of the insect recalls N. articulata, Sm., while the 

 details of the markings on thorax and abdomen remind one of A''. 

 (kcempunctata, Ckll. 



Nomada subvicinalis, sp. n. 



cJ* . — ^Length about Sh mm. ; pul^escence of head and thorax quite 

 abundant, brown dorsally, white on face, sides and under parts; head 

 and thorax black, rugoso-punctate ; facial quadrangle nearly square; 

 mandibles (except tips), labrum, clypeus, lateral face-marks and nar- 

 row stripe extending half-way up posterior orbits, lemon-yellow; lat- 

 eral face-marks extending as rather narrow bands up anterior orbits 

 as far as level of antenna, where they end abruptly, slightly bending in- 

 ward ; scape rather stout, yellow in front, black behind ; flagellum long, 

 bright ferruginous, with a black streak above on basal joints; third 

 antennal joint much shorter than fourth; upper border of prothorax, 

 tubercles, and a mark on lower anterior part of pleura, yellow; scutel- 

 Kim with two small and obscure red spots; thorax otherwise wholly 

 black ; legs bright red ; hind coxse black behind except at apex ; middle 

 and hind femora with a black spot beneath at base ; tegulae ferruginous ; 

 wings quite long, clear, dusky at apex ; nervures fuscous ; stigma rather 

 small, dull ferruginous; second submarginal cell subtriangular, much 

 narrowed above ; basal nervure ending some distance basad of trans- 

 verso-medial ; abdomen minutely roughened, bright orange-ferruginous 

 apex pointed rather acutely; extreme base of first segment with a 

 small black patch emitting three short prongs; sides of second and 

 third segments with a large rounded yellow spot, not at all pointed 

 mesad ; fourth segment with small lateral spots, sixth obscurely yellow ; 

 apical plate narrow, strongly notched ; venter pale ferruginous marked 

 with yellow, the yellow on second segment forming a large patch. 



Hab.—''i^o. Cal.,'' one in U. S. Nat. Museum. Related to A'. 

 vicinalis Cresson. 



Nomada marginella, sp. n. 



? . — Length about 7^ mm. ; head and thorax black, rugoso-punctate, 

 with white pubescence, rather abundant on face, cheeks, pleura, sides 



