BORNEAN DRAGONFLIES. 



327 



The males of these four species are at first sight very much 

 alike. They may be discriminated as follows : — 



A. Opaque colouring of hinder-wing begins at nodus or one or 



two cells before. Its margin runs transversely across the 

 wing; never a dark subcostal band extending to the wing- 

 base. 



Abd. 35 -f- 1 inm., li. w. 27-5 mm. P. tricolor Selys. 



B. Opaque colouring of hinder-wing begins about half-way 



between wing-base ;ind nodus. Its margin runs obliquely 

 outwards and backwards, and is rather in-egular ; usually 

 a hyaline indentation about 4-6 cells deep between 

 and Ou^. Dark band in subcostal space of all four wings 

 extending to wing-base in a.dult specimens, reaching the 

 nodus in the fore-wing. Apex of fore-wing tipped with 

 dark brown from the middle of the pterostigma. 

 Al)d. 30 -f 1 mm., h. w. 25 mm. P. subcostcdis Selys. 



C. Opaque area of hinder-wing begins at about two-thirds of 



the distance from the wing-base to tlie nodus, but area 

 betioeen M^+., R is ahvays hyaline wp to nodus. Dark 

 subcostal stripe not so well marked as in P. suhcostalis, 

 and scarcely indicated on the fore-wing, which also has 

 much less opacity at its apex. 

 Abd. 35 -f 1 mm., h. w. 28 -30 mm. P. suhnodalis Laidlaw. 



D. Hinder- wing opaque fiom the base to apex except for the 



1)asal space, and for certain quite irregidar areas which 

 in some specimens occur on the wings. Costal and sub- 

 costal spaces of fore-w^ing da.rk brown up to nodus, 

 Abd. 35 + 1 mm., h. w. 27-28 mm. P. hasalis Laidla.w. 



Unfortunately I do not know the females. 



These species probably all belong to the group P. variegata 

 (Ramb,). The group occurs in all parts of the Sondaic area. 



115. PsEUDOPH.flA IMPAR IN.EQUIPAR (Selys). 



PseudopJuea incecptijxir Kiid)y, Cat. Odonata, p. 1('a9, 

 4 d J. Tatau. 



At most these are but a local race of the older species P. impar 

 (Selys) from Malacca and Suniatra,. 



Its nearest allies seem to be P. dispar (Ramb.) and P. fraseri 

 Laidlaw from W. India, though the relationship is not very close. 



116. Dysph^a lugens Selys. 



Byspluea luge/ns Kirby, Cat. Odonata, p. 110. 



2 (5 6 . Limbang River, iv. 10. 1 $ (?). Retuh, 16. v. 14. 



The wings of the female specimen show in light hyaline brown 

 a colour-pattern identical with that of the male. 



S . Abd. 38 mm. + 1*5 mm., h. w. 32 mm. $ . Abd. 30 mm., 

 h. w. 29 mm. 



