430 Mr. R. M'Lachlan on 



nected by a black thread at the spiracle) . In the male there 

 is a triangular lateral blackish spot on the sides of segments 

 4 to 7 ; in the female these spots are much larger and occur 

 on segments 3 to 7, and are confused with the blackish under- 

 side ; in this sex segments 8 to 10 are wholly black, excepting 

 a reddish spot on each side of 8, and with paler margins above 

 on 9 and 10. Genitalia apparently not differing from those 

 of Th. erotica, and the appendages not appreciably different; 

 in both species (and probably also in tlie allies) the supe- 

 rior appendages are bifid at the upturned tips, and there are 

 one or two minute denticulations below the tips. In the 

 female the vulvar scale is perhaps more deeply divided and 

 the two obtuse apical side-lobes broader. 



In the wings the pterostigma is longer (3 to 3^ millim.) ; 

 ten antenodal nervules in the anterior wings of the male, nine 

 in the female. 



Length of abdomen, J 29 millim., ? 26^-27 millim. 

 Length of posterior wing, ^ 33 millim., ? 32-33 millim. 



Two males, four females. 



Although these examples (especially the females) vary 

 somewhat inter se, it seems to me that they form either a 

 distinct species or a marked local race. 



Libellula hasiUnea, sp. n. 



Closely allied to L. qnadrhnacuJata, L. ; differs especially 

 as follows : — In the anterior wings are tico hlachish streaks at 

 the base, viz. one in the subcostal area extending to slightly 

 beyond the orculus, the other occupying the whole of the median 

 area. In the posterior wings there is a streak in the sub- 

 costal area ; the triangular spot is comparatively small, 

 deeply excised beneath, deep black, and not reticulated with 

 yellow. 



Abdomen beneath deep blach, un'th seven isolated marginal 

 subqiiodrate yellow spots, that on the second segment small, 

 the others large, but gradually decreasing to the eighth 

 segment ; these spots are reproduced on the sides of the dorsal 

 surface, but are there more elongate. 



One pair ( c? ? ). 



As an additional character it may be stated that the costal 

 margin as far as the median vein is yellow for the whole 

 Icngtli of the wing, even in the postpterostigmatic area ; in 

 L. qvadrimaculata this sometimes exists as far as the nodus, 

 but not often beyond it. 



Thus the main {)oints in L. basilinca arc : — (1) The two 

 lines at the base of the anterior wings; (2) the triangular 



