Wasps of the Genus Tachytes. 



6. Clypeus with three well-defined teeth 

 on each side of the apical margin ; 



galea shorter thnn scape T. rhodesiana, Biscli. 



Cl^'peus without clearly defined teeth ; 

 galea much longer than scape 7. 



7. Eyes separated on the vertex by a distance 



not exceeding half the length of the 



second joint of the flagelluni 8. 



Eyes separated on the vertex by a 

 distance slightly exceeding three- 

 quarters of the length of the second 

 joint of the flagelluni ■ 10. 



8. Joints 3-7 of the flagelluni distinctly 



arcuate beneath ; eighth steruite shal- 

 lowly emarginate, the apical angles 



distinctly produced T. neavei, Turn. 



Joints of the flagellum not arcuate be- 

 neath ; eighth steruite truncate, the 

 angles not prod uced 9. 



9. Abdomen and the greater part of the 



antennje and legs ferruginous brown. . 1\ basilica, Gu^r. 

 Black, the apical margins of the abdo- 

 minal segments brown T. ohservabilis, Kohl. 



10. Eighth steruite truncate, the angles not 



produced T. velo.v, Sm. 



Eighth steruite deeply emarginate, the 



angles strongly produced T. perornata, Turn. 



11. Wings black, flushed with blue or 



violet; abdomen black, without pubes- 

 cent fasciae 12. 



Wings hyaline, subhyaline or flavo- 

 hyaliue, abdomen usually with pubes- 

 cent fasciae 13. 



12. Front and clypeus clothed with long 



black hairs T. nigi'opilosel'a, Cam. 



Front and clypeus with short, sericeous, 



silver pubescence T. natalensi?, Sauss. 



13. Abdomen black, without pubescent 



fasciae T. niidiventris, Turn. 



Abdomen with pubescent fasciae, some- 

 times interrupted 14. 



14. Two basal abdominal segments red .... T. ambidens, Kohl. 

 Basal abdominal segments black 15, 



15. Second to seventh joints of the flagellum 



strongly arcuate - dilatate beneath; 

 wings flavo-hyaline, pale fusco-hyaline 

 apically from the second cubital cell ; 

 pubescence of abdomen dense and 

 golden, sparse golden pubescence on 



the sides of the mesonotum T. dilaticornis, Turn. 



Flagellar joints at most feebly arcuate 

 beneath ; wings, if flavo-hyaline, 

 without a fusco - hyaline broad 

 margin , 16. 



16. Galea very long, considerably more than 



twice as long as the scape 17. 



