1902.] DRAGONFLIES OF THE " SKEAX EXPEDITION." 75 



belonging either to the genus Zygonidia or to Zygonyx, are 

 both males. 



The character of the last antenodal cross nervule seems to be 

 very variable. In one specimen of Zygonyx iris it is accident- 

 ally complete (de Selys, 0. R. Soc. Ent. Belg. xxxv. p. ccxxvii). 

 In one of the two known specimens of Zygonidia insignis it is 

 accidentally incomplete on one side (Kirby, A. M. N. H. (7) v. 

 p. 540). On one side of both specimens described above it is 

 incomplete, on the other complete. 



These two preceding species, together with their allies, pro- 

 bably constitute a separate section of the LihelluUnce approxi- 

 mating somewhat closely to the Corduliince. See Calvert, loc. cit. 



Onychothemis testacea, sp. n. (Plate Y. fig. 2.) 

 Length of abdomen 33*5 mm. Length of hind wing 40 mm. 

 Length of anal app. of c^ 2-5. Breadth of hind wing 13*5 mm. 

 Wings hyaline, reticulation black. Pterostigma 4 mm. long. 

 Fore wings. 15 antenodals, 10-11 postnodals. Internal ti-i- 

 angle divided into three cells. Discoidal triangle narrow, with 

 a single cross vein, followed by three rows of cells : no supra- tri- 

 angular nervule. Nodal sector waved, a single cross nervule in 

 the lower basal space ; membranule long, grey. Upper sector of 

 triangle curved. Sectors of arculus stalked. 



Hind wings. 9-10 antenodals, 11 postnodals. Discoidal triangle 

 free, followed by two rows of cells. Lower basal cell with a 

 single cross nervule. Sectors of triangle originate close together. 

 Nodal sector waved. 



Head. Yentral surfaces yellow, with a triangular black mark 

 in the centre, its apex directed forwards. Upper lip black, with 

 a reddish-brown spot on either side. Pthinarium and nasus 

 reddish brown, with a black mark along the suture between them. 

 Frons yellow below, steely black above. Frontal tubercle bifid, 

 steely black. Occipital triangle black. 



Prothorax black, with a yellow hinder margin. 

 Thorax dark metallic green, the mid-dorsal carina and a mid- 

 dorsal line between the wings yellow. Two small orange-yellow 

 spots on the humeral sutures on either side, the one above the 

 other. A thin yellow band runs from immediately behind the 

 front pair of wings downwards to between the second and third 

 pairs of legs on either side. An orange line runs along the outer 

 edge of the metasternum. Ventral surface black. 



Abdomen broad, slightly dilated at its base. Segments 4 to 8 

 strongly triangular in section. Testaceous black with dull yellow 

 markings. Mid-dorsal spots on the middle of segments 1 to 8. 

 Segments 2 and 3 with a yellow-marked transverse carina ; the 

 yellow mark is discontinuous dorsally in 2, but in 3 runs into 

 the yellow spot. Ventrally each segment from 3 to 8 has two 

 large oblong yellowish spots on either side of the middle line. 

 These spots extend round the lateral keel on to the sides of the 

 abdomen and on segment 7, 8 reach to within a short distance of 



