10 jMr. R. E. Turner on 



Subgenus Holotachytes, subgen. nov. 



Differs from typical Taclnjtes in tlie absence of tlie 

 incision on tlie outer margin of the mandibles, in the 

 striation of the dorsal surface of the median segment^ arid also 

 in the longer ami more rectangular shape of that segment. 

 Type of the subgenus, Tachytes dichrua, Sm, 

 Unlike Culotachytes this subgenus has the galea short and 

 broadly rounded at tlu^ apex, not rostrate ; and the joints 

 of the labial i)a!pi are short and stout. 



1. Tachytes {Holotachytes) dichroa, Sm. 



Tachytes dichroa, Sm. Cat. llyni. B.M. iv. p. 209 (18o6). d- 

 Larmdafero.v, Sm. Ann. & Mag. Nat. Hist. (4; xli. p. 29J- (1873j. $. 



Hah. Gambia (type S) ; N. Nigeria, Oye River near 

 Lajollo (J. W. Scott- Macjie) ; Gold Coast, N. Territories, 

 Wa (J. J. Simpson), May. 



Subgenus Calotachytes, subgen. nov. 



The three following species — T. marshalli, Turn., T. intra, 

 Kohl, and T. ad niirabilis/i! urn. — form a section of the genus 

 structurally distinguished by the five-jointed maxillary and 

 three-jointed labial palpi, other species of the geuus having 

 six-jomted maxillary and four-jointed labial palpi. The 

 basal joint of the labial palpi is extremely long and slender, 

 much longer than the second joint of the flagellum, and the 

 galea is very elongate. These two chai^actersi, however, aie 

 also present in T. observabi/is, Kohl, velox, Sm., and other 

 related species. I look on the difference in the number of 

 the joints in the palpi as of subgeneric importance. The 

 known species are confined to the Ethiopian region and are 

 of large size, and have at least the four basal dort^al seg- 

 ments densely covered with golden or silver ijubescence. 

 The secoiid sternite of the female is shining, with laige 

 sparse punctures. 



Type of the subgenus, Tachytes marshaUi, Turn. 



In addition to the three Ethiopian species noticed below, 

 T. argyropis, Sauss., from Madagascar, also belongs to the 

 subgenus. 



2. Tachytes {Calotachytes) marshalli, Turn, 



Tachytes marshalli, Turn. Ann. & Mag. Nat. Hist. (8) ix. p. 420 

 (1912). $d- 



i/fli.Mashonaland, Salisbury (G. A. K. Marshall); 



