1902. J ■ DRAGOXFLIES OF TIIK "SKEAX EXPEWTIOX." 387 



the pterostigma more oblique than the outer. PterostigniM Ijlack, 

 with pale margin, enclosed by a veiy thick black nerve. Median 

 and subnodal sectors united by a common stalk from their origin 

 as far as the first transverse nerve they encounter (on the right 

 fore wing beyond it for a short distance). Posterior tibias with 

 four pairs of black spines. 



Upper surface of the head dark green, upper lip dull bronze, 

 nasus black, antennfe brown, postocular surface dirty white. 

 Prothorax dull bi'own, dorsal surface of thorax bronze-green, 

 sides and under surface greyish white, pruinose. 



Abdomen (segments 1-7 only) bronze-black above, dull dark 

 brown below. 



Allied to T. superba from the Celebes and Moluccas. It differs 

 in details of coloration and in having only four spines on the 

 posterior tibias. 



*Tein'obasis ruficollis (Selys). 



*Archibasis melanoctana (Selys). 



Argiocnemis rubeola Selys. 



Ai^giocneinis rubeola Kirby, Cat. Odonata, p. 153. 



Race sumatrana'^. Kriiger, Stett. ent. Zeit. 1898, p. 126. 



1 S from Khota Baru, Kelantan. 



Argiocnemis nigricans Selys ? 



Argiocnemis nigricans Kirby, Cat. Odonata, p. 158; Kriiger, 

 Stett. ent. Zeit. 1898, p. 126. " 



4 c? , 1 5 from Khota Baru, Kelantan. 



Like Kriiger's specimen, mine are rather larger than Selys's. 



Length of hind wing, S 15, 5 16 mm. 

 ,, abdomen, c? 27, 5 26 ,, 



Postnodal nerves from 9 to 18 on the foi'e wing. The middle 

 lobe of the prothorax rather truncate, not rounded. 



The males diflfer from Selys's description in having segments 

 8-9 of the abdomen of a dull-brown colour (probably blue in the 

 living insect), whereas in the male described by Selys there is a 

 trilobed blue mark on the eighth segment. Otherwise the agree- 

 ment is fairly close. It should be remarked, however, that the 

 colour-pattern of my four male specimens shows no variation. 

 The female is exactly like that described by Selys as the female 

 of A. nigricans. I am disposed to think that the female described 

 by Selys as belonging to nigricans did not belong to the same 

 species as the male. His measurements suggest this. They 

 are : — 



Length of abdomen, J 22, $ 25-28 mm. 



,, hind wing, J 15, 5 17-19 „ 



If I am right, then, in taking this view, it follows that the 

 female of the true A. nigricans is as yet unknown, whilst my 

 specimens belong to a distinct species, ditfeiing from A. nigricans, 



25* 



