The genera of larval midges of Canada

This ecological diversity between the life stages was reflected in the two systems of classification that evolved; the larval and pupal system of Thienemann and his associates and the imago system of Edwards and Goetghebuer (see Brundin 1956). [...] The strongly sclero- tized, non-retractile head capsule, bearing the antennae and mouthparts, extends forward in the same plane as the longitudinal axis of the body. [...] They are either opposite to each other on the apex of the second segment or alternate on the apices of the second and third sesments. [...] Except in the Tanypodinae, and some Orthocladiinae, Diamesinae, and Chironominae, a seta interna arises fiom the base of the mandible pos- terior to the inner teeth (Figs. [...] The SI and SII in the Podonominae and the SII in the Tanytarsini are mounted on long tubular extensions of the setal socket (socles) (Fig.