162 PROCEEDINGS OF THE NATIONAL MUSEUM vol.75 



group as a single species, since I am unable to discover trustworthy 

 characters, based either on structure or color, that will enable me to 

 separate it into two or more species or even into well-defined varieties. 



MICROBEMBEX NATALIS. new species 



Figures 51, 52 



Type (female). — Black: clypeus; labrum; mandibles, except tips; 

 area on frons between antennae extended upward and narrowed to 

 a point connecting it with a spot below anterior ocellus ; scape below ; 

 broad anterior orbits deflected inward above anterior ocellus; pos- 

 terior orbits very broad below, narrowed above and extended across 

 the vertex a short distance, but not united ; prothorax, except trans- 

 verse spot above and vertical spot on side; lateral lines, and a U- 

 shaped spot whose anterior ends are much dilated, on scutum; 

 fascia, enlarged somewhat laterally, on posterior border of scutellum ; 

 fascia on metanotum; broad fascia on propodeum and its lateral 

 angles broadly; metapleura; mesopleura almost wholly; very broad 

 fascia on first tergite enclosing a pair of kidney-shaped discal marks 

 whose concave sides face laterally and whose anterior ends are further 

 separated than their posterior ends; broad, continuous fasciae on 

 tergites 2 — 5, whose margins are slightly sinuate; apex of sixth ter- 

 gite broadly; broad lateral spots joined by a narrow apical fascia 

 on sternites 2 and 3; lateral spots on sternites 4 and 5 prolonged 

 toward the midline but not connected ; coxae and trochanters in part ; 

 femora, except line above on all; tibiae, except line below on first 

 and second pairs and line above on third pair ; and tarsi ; yellom. 



The flagella are broken, only a portion of the base of one remains. 

 This i^ black above and rusty brown below. The wings are hyaline. 

 The clypeus is remarkably flat for a member of this genus, showing 

 scarcely any of the prominence so evident in monodonta. The pu- 

 bescence is white and remarkably short and sparse. The sixth ter- 

 gite bears basally well-defined lateral angles, which, owing to the 

 curvature of the tergite, point almost directly downward. This ter- 

 gite ends in a pair of well-defined points. 



It is just possible that the specimen on which this species is based 

 may belong to Smith's gratiosa, but if Smith's description of his 

 species is complete and accurate, it does not belong there. Further- 

 more, Handlirsch, who gives a figure of his species, unoguayensis^ says 

 that the abdomen of the female of gratiosa is quite similar to that of 

 uruguayensis. If his conclusions are correct, this female represents a 

 good species, for the sixth tergite is quite different from that of 

 v/mgumjensis as represented in the figure given by Handlirsch. 



