1902.] DRAGONPLIES OF THE " SKEAT EXPEDITION." 85 



lying over 4-6 cells. Behind the pterostigma are first two rows 

 of cells, then, after about five cells, only one row. 



Abdomen dark brown, with a green iridescence in some lights 

 on the first three and last three segments. Tenth segment very 

 short, not half as long as the ninth, ninth longer than the eighth. 

 Appendages shorter than the tenth, black, conical, and sharply 

 pointed. 



This species differs from E. uniformis Selys (? = E. tricolor 

 Kriiger) in having a smaller number of postnodal cells (it pos- 

 sesses 45 as against 60-65), in its i-ather smaller size, and in 

 the colouring of the wings, which are described by Kriiger as 

 being in the female yellow all over, especially at the base and 

 anterior margin, whereas in E. modesta the base of the wings is 

 perfectly transparent (Kriiger, Stett. ent. Zeit. 1893, p. 72 ; Selys, 

 Bull. Ac. Belg. (2) xlvii. p. 357, id. Ann. Soc. Ent. Belg.). 



There is a female in the British Museum from Mr. Ridley, 

 collected in Penang, belonging to this species. It has 37 ante- 

 nodals and 48 postnodals in the foi^e wings. Its abdomen is of a 

 dull dark red-brown colour. 



Olimacobasis, gen. nov. 



Basal area of wings reticulated. Pterostigma long ; quadri- 

 lateral long, rectangvilar ; arculus bent, sectors starting at the 

 same point just below its middle. Principal and subnodal sectors 

 rise at about the same level from the reticvdum, between the 

 upper sector of the arculus and the median nerve. 



The nervule closing the lower basal cell runs from the lower 

 sector of the arculus straight down to the lower extremity of the 

 lower basal cell. 



Olimacobasis lugens, sp. n. (Plate VI. fig. 5.) 



(Last three segments of the abdomen missing.) 



Length of abdomen (segmeiats 1-7) 42 mm. Length of hind 

 wing 47 mm. Breadth of hind wing 10 mm. 



Fore wing with 37 antenodals, 45 postnodal nerves. Ptero- 

 stigma covering 8-9 cells, abovit 2"5 mm. in length, very black. 

 Basal area with 8 cross nerves. 



Hind iving. 34 antenodals, 37 postnodals. Pterostigma as in 

 fore wing, basal area with 8 cross nerves. 



Head. Lower lip, base of the mandibles, and upper lip black. 

 Between the eyes, running forward as far as the epistome, is a 

 remarkable square milky-white patch of considerable size, taking 

 up in fact the greater part of the vertex. Along its hinder margin 

 it is notched in the middle by the anterior ocellus, which is sur- 

 rounded by a very small black ring which is continuous with a 

 rectangiilar black patch, in which lie the two posterior ocelli ; the 

 rest of the head is of a very dark bronze- green colour. 



Prothorax dark green, almost black. 



Thorax. Dark metallic green above, with all the sutures and 



