Published online by Cambridge University Press: 10 July 2009
♂ ♀. Length, ♂ (15 specimens) 8 to 8·5 mm.*, ♀ (15 specimens) 9 to 10 mm.; width of head 2·8 to 3 mm.; width of front at vertex, ♂ 0·75 mm., ♀ 1 mm.; length of wing, ♂ 8 to 8·75 mm., ♀ 9·4 to 10 mm.
* A specimen in the Museum collection with its abdomen distended by coagulated blood measures 9·4 mm. in length.
† There is a fringe on the third joint of the antennæ but it is so short and the hairs composing it are so minute as to be scarcely noticeable when the joint is examined in profile under an ordinary platyscopic lens.