BY R. J. TILLYARD. 489 



the triangle of the forewings. In the latter genus this triangle is 

 normal, i.e., it arises just about the arculus, and not quite beyond 

 it as in Tetrathemis. 



ii.— Subfamily CORDULIIN-ffi. 

 10. Synthemis nigra, n.sp.(£. guttata \a.r. punctata Martin). 



£. Total length 50 mm.; abdomen 38 mm.; wings, fore 34mm., 

 hind 33 mm. 



Wings rather slack; neuration black, costa yellowish out- 

 wards for some distance; a distinct "white round spot at the base 

 of the costal nervure of all the wings. Basilar space with two or 

 three cross-nervules; anal margin of hind wings obtusely angu- 

 lated. Pterostigma 2 - 5mm., narrow, black. Membranule, fore 

 nil; hind l'5mm., thick, dark brown. Nodal Indicator 1 , 14 8 



1 10 10 



Head: Vertex hairy, black; eyes brilliant dark green in the 

 living insect ; ocelli and antennce black. Front hairy, cleft 

 medially, minutely punctate, black, with two large pale patches 

 separated by the median cleft Each patch is composed of two 

 conjunct spots; the inner being rounded, chalky white; the outer 

 triangular, dull greyish. Clypeus: postclypeus black, anteclypeus 

 brownish with a central white triangular spot; labrum black; 

 labium very pale yellowish-brown; mandibles brown. 



Thorax: Prothorax black. Meso- and metathorax black with 

 metallic green reflections; dorsal suture rather deep, marked with 

 a pale grey line; just behind the suture are two slanting white 

 spots, close together. On either side a greyish band; below this, 

 close to the underside, another shorter band; mesoscutum round, 

 white; metascutum greyish; underside dirty greyish. Legs black, 

 coxae, trochanters and part of fore femora dirty brown. 



Abdomen thin, much pinched at 3; 3-5 widening, 6-10 

 cylindrical. Colour deep black; 3 has a pair of small oval greyish 

 spots, basal, close up to suture; 10 slightly swollen below, hairy. 

 Underside deep black, 1 with a transverse grey band; genital 

 appendages of 2 surrounded with grey. 

 35 



