254 Mr. R. E. Turner on Fossorial Hymenoptera. 



apex. The basal joint of the fore tarsi has four long spines 

 on tiie outer margin ; the tooth near tlie middle of the tarsal 

 ungues is small. The dark apical border of the fore wing 

 roaelies the first transverse cubital nervure. First abscissa 

 of the radius as long as the second and third combined, the 

 two recurrent nervures very near to each other on the cubitus.^ 



Hah. Offi, N. Nigeria {Uiscock). 



Tliis species is very near lirotdes, Turn., and may prove 

 to be a western subspecies of that insect. It differs in tlie 

 broader pygidial area, in the shape of the anterior margin of 

 the clypeus, in the reddisli-brown margins of the abdominal 

 segments, and in the darker and somewhat broader marginal 

 band of the fore wing. 



The superficial resemblance to Liris hcemorrhoidalis is 

 very striking. 



Key to the Australian Species of Tachysphex. 



2$. 



1. Two basal segments of abdomen red .... T. truncatifrons, Turn. 

 Abdomen whullj black 2. 



2. Tibiaj, tarsi, and apex at least of the 



femora ferruginous or testaceous brown. 3. 

 Tibiae and femora wholly black, tarsi 

 usually black, sometimes testaceous 

 brown towards the apex 4. 



3. Legs ferruginous, liind and intermediate 



femora wholly ferruginous T. adelaida;, Turn. 



Legs testaceous brown, hind and interme- 

 diate femora black except at the apex . T. imbellis, Turn. 



4. Wings fuscous or dark fusco-byaline .... 5. 

 "VN'inijs hyaline 7. 



5. Pygidial area distinctly though not very 



closely punctured ; comb of the fore 



tarsi black and long T. stimulator, Turn. 



Pygidial area smooth and shining ; comb 

 of the fore tarsi shorter and fusco- 

 ferruginous 6. 



6. Wings dark fuscous ; mesonotum, scu- 



tellum,and abdomen highly polished. . T. persistans, Tom. 

 Wings dark f usco-hyaline ; mesonotum, 



scutellum, and abdomen subopaque . . T. hypoleius, Sm. 



7. Dorsal surface of median segment rugose- 



reticulate or longitudinally striated . . 8. 

 Dorsal surface of median segment smooth 

 or minutely punctured 9. 



8. Median segment longitudinally striated; 



third abscissa of the radius longer than 



the second T. icalkei-i, Tarn. 



Median segment rugose-reticulate ; second 

 abscissa of the radius at least twice as 

 long as the third T. rut/ilorsatHx, Turn. 



