NO. 2173. A REVISION OF THE BEMBICINE WASPS— PARKER. 23 



radial vein, which extends ahnost to the apical border of the wing. 

 The median cell is long and distally bears two longitudinal veins 

 (prolongations of the cubitus and radial) extending to near the border 

 of the whig. The cubital vein arises at some distance from the sub- 

 median cell. The posterior angle of this cell, formed by the junction 

 of the submedian and submedian cross veins is obtuse. The legs are 

 relatively long and slender and, as in related genera, the middle coxae 

 are not contiguous. In the female the combs of the anterior tarsi 

 are strongly developed; in the males they are weakly developed or 

 lacking. In the case of the male of many species the middle femora 

 are serrate, dentate or emarginate. Likewise the middle metatarsus 

 may be curved, in wliich case the imicr curved surface may or may 

 not bear a number of spines. In many species the tarsal segments 

 especially the ultimate segments are more or less dilated and flat- 

 tened. The tarsal claws are long, slender, and simple, but in one 

 species those of the first pair of legs are modified and are not sym- 

 metrical. In many species the pulviUi are large and conspicuous; 

 in others, much reduced or lacking. In one species the hind femora 

 are emargmate. 



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

 bears the lateral stipites, the median spatha below which lie the sag- 

 ittae. The stipites are large, more or less strongly chituiized, variable 

 in form but never smiilar m general outline to those of Stictia. The 

 median spatha is deeply cleft at the distal end, the two parts strongly 

 chitinized, rounded and curved downward. At some distance from 

 the distal end of the spatha on either side there is a short projection, 

 hke the barb of an arrow, somewhat similar to that fomid in the case 

 of Bemhix. As in related genera the sagitta is divided near its base 

 into two parts. The mner division is strongly chitinized, rounded, 

 curved and usually ends in a sort of hook. In the exserted genitalia 

 the imier divisions of the two sagittae lie side by side directly below 

 the spatha. The outer division of the sagitta is the shorter of the two, 

 less strongly chitinized and usually somewhat hirsute. 



KEY TO SPECIES. 



Males. 



1. Medial metatarsus more or less strongly curved; inner curved surface frequently 

 beset with several spines 2. 



1. Medial metatarsus not ciu-ved 12. 



2. Second sternite nontuberculate 3. 



2. Second sternite unituberculate 7. 



2. Second sternite bituberculate 8. 



3. Medial femora smooth beneath pictifrons. 



3. Medial femora serrate or dentate beneath 4. 



4. Pulvilli large and distinct; apical segment of all tarsi black; those of the anterior 



pair dilated and flattened .formosa. 



4. Pulvilli indistinct; tarsi normal 5. 



