DRAGONFLIES FROM BANGKOK. 235 



nervure and more so than is usual even in Agriocnemis; the tri- 

 gones are not very acutely pointed and rather wider than is usual 

 for the genus; 8 postnodal nervures in the forewing, 6 in the hind. 



Legs white, the extensor surface of the femora black, as is 

 also the last joint of the tarsus. Tibia? armed with 3 to 4 long 

 spines on the Outer side, with a row of numerous, smaller ones on 

 the inner side. Claw -hooks robust, situated nearly at the end of the 

 claws. 



22. ISCHNURA SENEGALEXSIS Ramb. 



23. PSEUDAGRION SIAMEXSLS, sp. llOV. 



(Fig 2. a). 



Male. Length of abdomen 30 mm., of hindwing 19 mm. 



Head pale sky-blue with a narrow, transverse, black stripe 

 crossing the vertex at the level of the ocelli and throwing a projec- 

 tion back just to the outer side of the ocelli which, meeting the black 

 on the occiput, encloses a large,, subtriangular spot of azure blue 

 behind each eye. Eyes dark brown above, greenish below. 



Prothorax blue with longitudinal, black, mid-dorsal, sub-dorsal 

 and lateral lines which coalesce anteriorly and posteriorly to enclose 

 spots of the ground colour. 



Thorax azure blue, paler at the sides, marked with a mid-dor- 

 sal, narrow black stripe and narrow humeral bands of the same 

 colour. 



Wings hyaline, stigma lozenge-shaped, blackish ; postnodal 

 nervures 9 in the forewing, 7 in the hind. 



Abdomen blue on the dorsum, paler on the sides and chang- 

 ing imperceptibly to yellowish below. Segment 1 marked with a 

 dorsal, quadrate, black spot which does not quite reach the apex ; 

 segment 2 with a narrow, basal annule, pointed in the middle and 

 an apical, goblet-shaped marking extending onty to the middle of 

 the segment, quite square basally and with a very short stem apically 

 where it joins an apical ring; segments 3 to 6 with long, black, 

 dorsal stripes which taper basally and expand apically just before 

 the distal end where they join apical annules ; segment 7 similar but 

 with no apical contraction after the expansion ; segments 8 and 9 



VOL. IV, NO. 4, 1922. 



