Abstract
Sporogony of Leucocytozoon mirandae, Leucocytozoon bonasae, and Leucocytozoon fringillinarum occurs in Simulium aureum as well as other species. Sporogony of some individuals is completed in less than 5 days at 22° ± 2 °C; others require 9 days or more. Oöcysts of mirandae averaged 14 μ (9–19) in diameter, those of bonasae 13 μ (8–16), and those of fringillinarum 11 μ (8–16). The sporozoites of mirandae were slightly longer and narrower than those of the other two species and were more numerous in the larger oöcysts.