ART. 5 GENERIC REVISION OF THE FOSSORIAL WASPS PARKER 157 



13. Clypeus unusually prominent, the depth of its apical emargination is to the 



greatest width of the emargination as three is to four sulphurea. 



Clypeus less prominent, depth of the apical emargination as compared with 

 the width of the emargination not as above 14. 



14. Clypeus, scape, mesopleura, and large discal spots on scutum, yellow aurata. 



Combination of maculation as given above not present monodonta. 



MICROBEMBEX BIDENS, new sipecies 

 Figures 56-59 



This species diflfers from all other species of the genus so far 

 described, in that the anterior metatarsus on both males and females 

 is provided with eight spines. The clypeus is very prominent and 

 the depth of its apical emargination is to the width of the emargina- 

 tion approximately as four is to five. The maxillary palpus is 

 composed of four segments, the labial of two. The seventh tergite 

 of the male bears a pair of lateral apical spines and the median ter- 

 minal portion is broad and emarginate at the apex (fig. 59). The 

 male genitalia are distinct, as shown in Figure 57, and the spine on the 

 eighth sternite bears on its ventral surface a short spine (fig. 56). 

 The second sternite of the male near its posterior border bears a 

 transverse, swollen area, which bears at its posterior midventral 

 point a short, pointed tubercle. The apex of the sixth tergite of the 

 female is deeply emarginate, causing the tergite to end in a pair of 

 short spines (fig. 58). The pubescence on the head, thorax, and 

 propodeum is short, relatively sparse and somewhat silvery, espe- 

 cially on the frons. The wings are hyaline. 



Ti/pe (male). — Black: labrum; mandibles, except tips; clypeus, 

 except black border at base ; scape, except small spot above ; anterior 

 orbits shortened and narrowed above; spot below anterior ocellus; 

 posterior orbits; posterior border of pronotum and of sides of 

 prothorax, including tubercles; lateral lines broad anteriorly and 

 pair of discal lines on scutum ; fascia on scutellum greatly narrowed 

 at midline; fascia on metanotum; broad, curved fascia on pro- 

 podeum; lateral angles continuous with sides of propodeum; large 

 spot on mesopleura; broad, continuous fasciae on the tergites 

 (rendering the dorsum of the abdomen, when straightened, almost 

 entirely yellow) ; second sternite almost wholly; continuous fasciae 

 on sternites 3-7, narrow on the more posterior sternites; legs, ex- 

 cept some black on coxae, trochanters, and femora above; yelloio. 



The allotype (female) differs in color but little from the type. 

 There is no black on the clypeus; the posterior orbits are extended 

 on the vertex; the fasciae on the tergites and sternites are not quite 

 so well developed ; and the black on the femora is a little more 

 extensive. 



