AST. 5 GENERIC REVISION OF THE FOSSORIAL WASPS PARKER 1 1 



In this genus the mandibles are edentate, a character not present 

 in either of the other genera of the tribe. The inner eye-margins 

 are convergent at the clypeus and the posterior-lateral angles of the 

 propodeum are rounded. 



Head broad as thorax; inner eye-margins distinctly convergent at 

 the clypeus; labrum rather strongly arched, its dorso-ventral length 

 about equal to its width; mandibles edentate; posterior surface of 

 propodeum flat, posterior-lateral angles rounded; radial cell shorter 

 than the first cubital cell, which is less than one and one-half times 

 as long as the radial; second cubital cell not petiolate, but the first 

 and second cubital cross veins may have a common point of union 

 with the radial ; second abscissa of both radiella and cubitella present 

 and approximately parallel; first abscissa of discoidella longer than 

 the width of the mediellan cell ; tenth flagellar segment of male with 

 conspicuous process ; eighth sternite of male ending in three spines. 



Tribe BEMBICINI 



With the exception of the genus Beiiibix^ which is world wide in 

 distribution, members of this tribe are confined to the Western Hemi- 

 sphere. The ocelli are either completely reduced to cicatrices or are 

 to a greater or less degree distorted. In some species the ocelli are 

 still provided with more or less well-formed lenses, but whether 

 these lenses are functional is a matter of conjecture. The labrum is 

 well developed; its dorso-ventral length always exceeds its greatest 

 width, and in some species its length is several times its width at the 

 base. The tibia of the mesothoracic leg is provided with only a single 

 spur. The submediellan cell does not extend beyond the junction 

 of the mediella and cubitella veins. 



KEY TO THE GENERA OF BEMBICINI 



1. Maxillae unusually long, reaching the posterior coxae when at rest and in- 



capable of being concealed behind the labrum ; maxillary palpus composed 



of three segments; labial composed of one Steniolia, 



Maxillae when at rest concealed behind the labrum, or if elongated never 

 reaching the posterior coxae; maxillary and labial palpi otherwise (in 

 all genera except Microbembex) 2, 



2. Anterior ocellus (or cicatrice) placed in a pit, the borders of which are dis- 



tinctly elevated Stictiella. 



Anterior ocellus (or cicatrice) not placed in a pit 3. 



3. Posterior surface of propodeum (median segment) concave, its posterior- 



lateral angles prolonged, compressed, and wedgelike (in one species the 



posterior-lateral angles are rounded) Bicyrtes. 



Posterior surface of propodeum (median segment) flat or convex; posterior- 

 lateral angles rounded 4. 



4. Mandibles edentate 5. 



Mandibles dentate (in some species teeth on inner margin of mandible may 



be vestigial) 6. 



