70 Mr. W. F. Kirby on Odonata from Sierra Leone. 



mature specimens the vertex is violet and the thorax pruinose 

 blue. The sides of the mentum are sometimes yellow. 

 Wings hyaline, with black nervures ; fore wings with 11-13 

 antenodal and 7-10 postnodai cioss-nervures ; pterostigma 

 dark brown, traversed by a narrow yellow line. Triangle 

 traversed, followed by three rows of cells, increasing; sub- 

 triangular space consisting of 3 cells : hind wings with 7-8 



Fier. 1. 



Trithemis serva. 



antenodal and 9-11 postnodai cross-nervures ; membranule 

 white, stained with blackish ; a small yellow cloud beyond, 

 sometimes obsolete, with its outer border straight, and above 

 the lower basal cell, only visible at the extreme base. Ap- 

 pendages of the second segment very prominent, the two 

 hindermost converging like a pair of pincers. 



Described from six specimens, two of them taken by 

 Mr. Austen on Sept. 5 and 21 (1899). 



Allied to the East-Indian T. /estiva, Ramb., but easily 

 distinguished by the different shape of the markings at the 

 base of the hind wings and the form of the appendages of the 

 second segment of the abdomen. It must also be allied to 

 T. dichroa, Karsch, which seems to be a still darker coloured 

 species in the male. 



Belothemis dorsalis. 



Libellula dorsalis, Eamb. Ins. N6vr. p. 89 (1842). 



Trithemis dorsalis, Kirb. Cat, Neur. Odon. p. 19. n. 16 (1890). 



Helot kemis dorsalis, Karsch, Berl. ent. Zeitschr. xxxiii. p. 378 (1890). 



10 specimens, Aug. 19, 26, Sept, 8, 9, 13, 19, 20, 21 (1899). 

 I am not satisfied that this genus is sufficiently distinct 

 from Trithemis. 



