North America; Palearctic name. Research conducted by Rawson (1953) in Great Slave Lake between 1944 and 1947 noted that Lebertia porosa was the most numerous and widespread species in their collections. The species was common at Pearson Point, Yellowknife Bay and near the outlet of the lake. More than 200 specimens were taken from the stomach of one round whitefish (Prosopium cylindraceum).