Mayfly Species Cinygmula mimus

A rather large species, the wings tinged with yellowish brown; spine on inner margin of each side of penes only.

Head reddish to purplish brown. Thoracic notum light chestnut brown; remainder of thorax yellowish brown with reddish tinges; paler yellowish or creamy areas anterior to wing root, and below bases of wings on pleura. Legs light yellowish brown; tibia-tarsal joint and tarsal joinings of fore leg darker brown; claws of all legs brownish; tarsal joinings of middle and hind legs narrowly brown, distal tarsal joints tinged with light brown. Wings hyaline, the membrane tinged with yellowish brown, especially evident in hind wing and basal half of fore wing. Venation light yellowish brown, the cross veins often faintly red-brown. Abdominal segments 2-7 semi-hyaline, pale purplish to light madder brown; extreme anterior margin colorless, posterior margins narrowly darker. Sternites very similar to tergites, but somewhat paler; no dark mid-ventral markings. Segments 8-10 opaque, yellowish brown with a tinge of purple or madder; sternites more yellowish than tergites. Tails yellowish brown, often with faint red-brown tinge in basal portion; joinings opaque, faintly darker. Forceps light red-brown, penes yellow-brown; penes divergent almost from base, bearing on each side a single spine on inner margin. (See fig. 103, gartrelli).

The yellowish brown tinge of the wings, the absence of dark ventral markings and the details of structure of the penes, when taken together, distinguish this from other allied species.