The Oilonata or Drtigonflies of South Africa. 341 



tlian tenth segment. On dorsum of tenth segment an acute process whicli 

 fits into a groove on dorsum of ninth segment. Female with vulvar scale 

 long and narrow, fitting into a corresponding groove on ventral plate of 

 segments 9 and 10 .. .... Ceratogomphus. 



PODOGOMPHUS (Karsch, 1890). 



A genus of African, mostly East African, distribution ; a small 

 number of species are described from a very limited number of 

 specimens. Podogomphus is closely allied to the large palaeonearctic 

 genus GompJius, from which it differs chiefly by the extremely 

 developed third pair of legs ; the neural characters, type of genitalia 

 and appendages, and the colour system being much the same as in 

 Gomphus. 



PODOGOMPHUS PRA.ETORIUS (Selys, 1878). 



S. Afr. Mus. : 1 #, M'Fougosi, Zululaud (xii . 1911, W. E. Jones) ; 

 1 , Barbertou, Transvaal. Brit. Mus. : 1 , Mazoe, 4000 ft., Mashona- 

 land (29 . xii . 1905, Marshall). Coll. K. J. Morton : 1 $ , Stutterheim 

 (13 . i . 1908, Miss Fountaine). Mus. Tervueren : 1 ? , Elizabethville, 

 Katanga (9 . iii . 1912, Dr. Bequaert). 



Colours in adult specimens very light yellow with a shade of 

 greenish, and deep black. 



J. Labium, labrum, face and frons yellow ; a narrow and slightly 

 diffuse transverse black line in the middle of anterior surface of frous, 

 slightly curved dorsal in the middle to touch an opposite curve of the 

 frontal ridge. Base of frous rather narrowly black (less than one- 

 third of dorsal surface). Vertex black with a narrow laterally incom- 

 plete black line at the ocelli. Occipital plate yellow, the free margin 

 narrowly bordered with black, slightly convex, with black lines. On 

 vertex a narrow transverse ridge, rounding the ocelli in a lateral 

 curve ; in front of its median straight part a second, more obtuse 

 transverse ridge between the lateral ocelli. Thoracic pattern, Plate IX, 

 fig. 1. Legs robust, the first pair the shorter, third pair very long 

 (femora 10 mm.). Third femora besides the regular two rows of 

 short spines with 3-4 long and very acute spines at the medial, 2-3 

 equal spines at the lateral side. Legs mostly yellow, black lines on 

 first and second femora rather broad, very narrow on third femora ; 

 internal side of tibiae black ; tarsi black. 



Abdomen slender, segments 1-2 slightly dilated, 3-10 almost 

 regularly cylindrical and comparatively long. Yellow complete lateral 

 black bauds from 1 to 10, distant from the lateral margins by slightly 

 22 



