NO. 2173. A REVISION OF TUB BEMBICINE WASPS— PARKER. 17 



The abdomen is relatively stout and wddest at the junction of the 

 first and second segments. The tergites are strongly arched, the 

 sternites flat. The ultimate tergite of the males is provided vnth 

 prominent lateral processes or spines and the median prolongation is 

 cmarginate at the end. The ultimate lergite of the females lacks 

 the spines, is rounded apically, and its surface, punctate or shghtly 

 rugose, is without a pygidial area. On the second sternite of the 

 male there is a median prominence or carina more or less well devel- 

 oped; this is also discernible on the females of some species, but on 

 others it is wholly lacking. The sixth sternite of the male bears a 

 conspicuous median area that is shghtly raised and is finely punctate 

 or granular. The eighth sternite of the male ends in a single, stout, 

 curved spine. 



The male genital armature consists of a basal piece (cardo) which 

 bears the lateral stipites, the median spatha, and below this the 

 sagittae. The stipites are strongly chitinized, long, curved, and 

 pointed. The spatha is roimdly dilated at the end and bears a deep 

 median cleft. The form is distinctly different from that in any of 

 the closely related genera. The sagitta is a divided structure; the 

 dorsal or inner part, the longer and the more slender of the two, is 

 wealdy chitinized and somewhat hirsute; the ventral or outer part 

 is heavier, shorter, not strongly chitinized and very hirsute. 



The legs are relatively long and strong. The middle coxae are 

 separated. The middle femora of the males bear near the distal end 

 on the lower border a conspicuous, curved, distaliy directed tooth. 

 All tibiae and tarsi in both sexes are beset with spines, which are 

 better developed in the female than in the male. In both sexes the 

 anterior tarsi are provided with tarsal combs, which are much better 

 developed in the females than in the males. The pul villi are large 

 and conspicuous and the middle tibiae bear at the distal end a single 

 spur. 



The wings are much hke those of BemUx. The pterostigma of the 

 anterior wing is obhterated. The radial cell is long, narrow, of 

 nearly uniform width and rounded at the distal end, which lies on the 

 costal border of the wing. The first cubital cross vein, as in Bembix 

 near its posterior end is strongly bent toward the proximal end of the 

 wing. The second cubital cell, which receives both discoidal cross 

 vems, is much wider on the cubital vein than on the radiiil. The 

 third cubital cross vein is deflected toward the distal end of the wing 

 and at the posterior end is rounded so that the third cubital cell 

 extends as far toward the distal end of the wing as does the radial 

 cell. The angle formed by the junction of the radial and third cu- 

 bital cross veins and opening outward is acute. The first submedian 

 cell is longer than the second, which steadily increases in width 

 65008°— Proc.N.M. vol.52— 17 2 



