412 Mr. R. M'Lachlan on some Odonata 



base on either side of the carina there is a strong tubercle ; 

 superior appendages comparatively short and thick (6 inillim.) , 

 about as long as the eighth and ninth segments united, black, 

 externally nearly straight, slightly sinuate before the apex ; 

 internally they are thick at the base and scarcely excised on 

 the edge, but triangularly dilated before the apical portion (at 

 a point where a carina extending from the base finishes), 

 which latter is very oblique, ending externally in an incurved 

 sharp tooth ; viewed laterally these appendages are gently 

 curved, the inner edge ciliated ; inferior appendages fully 

 two thirds the length of the superior, very elongately trian- 

 gular, strongly curved if viewed laterally, the apex slightly 

 inturned (doubtfully emarginate). 



Wings broad and obtuse, hyaline, tinged with yellow at 

 the base in the subcostal and median areas, brownish in the 

 former, extending nearly to the arculus in the posterior ; 

 pterostigma brownish yellow (4^ millim.), surmounting 4 or 5 

 cellules ; membranule small, whitish ; neuration moderately 

 dense, black ; subnodal sector furcating much before the 

 level of the pterostigma, with 3 or 4 rows of cellules between 

 the branches (9 on the margin) ; 4 cellules between the sub- 

 nodal and interposed sector at the widest part, 2 on the margin ; 

 one row between the sectors of the triangle ; no basal sub- 

 costal nervule ; 24 antenodals and 24 postnodals in the ante- 

 rior, and 18 to 22 in the posterior ; 6 cellules in the principal 

 triangle in the anterior and 5 in the posterior, 2 in the inner 

 triangle, 6 supra-trigonals and ,5 or 6 in the median area ; 

 3 cellules in the anal triangle. 



$ . As in the male, but the abdomen only slightly con- 

 stricted at the third segment ; appendages very slender and 

 acute, as long as the ninth segment ; tenth ventral segment 

 with two long curved teeth. 



Wings becoming fumose, especially at base and apex, in 

 very adult individuals ; the yellow of the base more strongly 

 defined than in the male, extending nearly up to the triangles, 

 and the brown much more evident, extending up to and 

 beyond the arculus ; 25-28 antenodals and 19 or 20 post- 

 nodals in the anterior, and 21-23 and 20-22 in the posterior. 



Length of abdomen, $ {cum append.) 54 millim., ? 52-54 

 millim. ; length of posterior wing, $ 45 millim., ? 46-50 

 millim. ; greatest breadth 15-16^ millim. 



Hob. Khasia Hills, two males, three females; Annam, one 

 female. 



Quite distinct from G. subinterrupta and basiguttata (which 

 also have the wings marked with brown at the base) by the 



