584 WEST AFRICAN INSECTA AND ARACHNIDA RILEY. 



Libellula (Orthetrum) capensis n.sp. (alviTt. (Fig. 3.) 

 T.ihrJIuhi assimiliii Hjijfcii MS. 



(J. Vertex reiUlish, in front hlack, tip liilid, apices acute. Frous leddisli yellow, 

 sides lighter, };roove<l above, front separated from each side by a vertical carina, the 

 two carina' united by a luu'izontal carinajnst above the lower margin of the frons. 

 Nasus and rhinarium luteous. Labrum reddish yellow. Labium and its lobes lirown 

 Occiput retUlish brown. 



Prothorax with anterior lobe brown, posterior lobe yellowish, broad, its hindmar- 

 giTi slightly notclic<l in the middle. 



Dorsum of thorax luteous, a faint indicat ion of a brownisli si)ot on each side of the 

 median crest near its summit, and a brown humeral stripe. Sides yellowish, obscure, 

 with ill-defined brown marks around the lateral sutures. 

 Feet luteous, tibiae darker, apices of femora and tarsi black. 



Abdomen rather vslender, compressed at base, slightly contracted at the fourth seg- 

 ment becoming wider to the sixth, but not so wide as at base ; from 6 tapering gradu- 

 ally CO apex. First three segments luteous, an ill-delined brown strijje each side. 

 Dorsnm of remaining segments pruinose, nnder side of abdomen luteous. 



Genitalia a little prominent. Anterior lamina with 

 sides rounded to the apex, which is truncated. Hamule 

 bifid, Itranches of equal length, straight, almost parallel, 

 separated by but a short interval; inner branch Idack, 

 slender, apex rounded, with a slight hook ; outer branch 



*'^*^'' "^^ . luteous: much thicker, apex rounded. Genital lobe broad, 



( ii-ijitalia of Libellula capi'iisis i , i ■ 



cfn.Bp. apex rounded, hairy. 



Superior appendages black, about as long as the ninth segment, similar to those 

 of J), dilataia (i{. v.). Inferior appendage luteous, sides blackish, similar to that of 

 dUatata. 



Wings hyaline, somewhat milky, a very slight yellowish cloud at base. Reticu- 

 lation blackish, costa luteous cxtcriorlj'. Pterostigma, brownish yellow, three to 

 four times as long as broad, surmounting two and parts of two other cells. Mem- 

 branule blackish. Sectors of the arculus stalked. One basilar cross vein placed 

 very nearly on a level with the first antecubital. Nodal sector waved. F'ron- 

 wings with one hypertrigonal; 13 (right), 15 (left) antecubitals, the last one cont 

 tinuous; 11 postcubitala ; discoidal triangle with one cross vein; internal tiiangle 

 of three cells; three rows of discoidal areolets. 



Hind wings with no hypertrigonals ; 10 (right), 11 (left) antecubitals, the lastoi.e 

 continuous; 11 (right), 10 (left) postcubitals; discoidal triangle free, its inner side ' 

 slightly nearer the base than the prolongation (»f the arculus would be; no internal 

 triangle; two rows of discoidal areolets, increasing; sectors of the triangle a little 

 separated at their origin. Total length, 49 millimeters. Abdomen (inch app.), 33.5 

 millimeters. Superior appcTidagcs, 2 millimeters. Front wing, 31.5 millimeters. 

 Hind wing, 33 millimeters. Pterostigma, 3.5 millimeters. 



One male from Cape Town. Dr. Hagen examined tliis specimen and wrote to me 

 (September 2, 1890) it "is my L. assimilis, never i)ublished." This species belongs 

 to the genus Orthetrum of Kirby's Revision. 



Libellula (Orthetrum) caffra liurmcister. (Fig. 4.) 



Dr. Hagen has detcrmiued two specimens for me as Itelonging to this species. 

 They are a male from Congo and a female from Freetown, Sierra Leone. Loth have 

 a considera))le i)ortiou of the .'ibdomens wanting. 



In his Revision of the Subfamily Libellulina (Trans. Zool. Soc. London, xii, 

 pp. 249-348, 1S89), Mr. W. F. Kirby refers eujfra to his new genus Thcrmorthemis 

 (p. 289). I think it rather belongs to his genus Orthetrum. Thcrmorthemis is stated 

 (/. c.) to have the triangle in the forewings followed by four or five rows of cells; 



