A NEW EPHEMERELLA FROM ILLINOIS (EPHEMEROPTERA)

Extract

Male. Head and thorax deep black-brown, pleura tinged with lighter brown: the mesothorax broad for the size of the insect and with the axillary cords scarcely extended beyond tip of scutellum. Abdomen with segments 1-6 and the anterior half of 7 dull semibvaline whitish with traces of a fine ruddy dorsal line and lateral rows of small ruddy spots or streaks situated one on each segment in the central area: posterior half of 7 and 8-10 opaque pinkish brown, paler ventrally: forceps pale tinged with brown a prominent tubercle situated between the limbs at base:setae white unbanded. Fore legs with the femora light sepia-brown tibiae and tarsi dull whitish the former shaded slightly with sepia at base tibia rather long more than twice as long as the femur and subequal to the entire tarsus: mid and hindlegs whitish the femora tinged with brown, femora and tibiae subequal. Wings hvaline with a brown tinge at extreme base: veins and crossveins pale. Length of body, 5 mm : of forewing 5 mm.