Mayfly Species Traverella albertana

Head and thorax deep black; membranous portions of the pleura slightly tinged with ruddy. Coxae and trochanters of legs black. Femora reddish brown, the bases and apices tipped with black; tibiae and tarsi pale, with a brownish tinge; a black ring at the base of the tibia. Fore wings semi-hyaline, the basal half strongly tinged with smoky; veins black, cross veins numerous and fine, black except the basal costal cross veins, which are obsolescent. Hind wings largely smoky; the blunt costal projection is before the middle of the wing.

Abdomen dorsally dirty whitish, marked with broad slightly oblique bands of deep smoky; pale areas are thus left of the anterior and posterior margins, giving the abdomen a ringed appearance. Sternites more evenly smoky black, ringed with whitish. Forceps dull yellowish; two fine long spines project backwards from the forceps base (see fig.146). Tails whitish.