Sensu Moller Pillot, 1984a (sub. Microtendipes gr. tarsalis)
Body
Large larvae up to 15 mm long. No lateral and ventral tubules. Procercus and anal tubules present (Wiederholm, 1983; Chernovskij, 1961).
Head
The clypeus is separate from the frontal apotome. A subapical pit is absent and labral sclerite 1 are absent.
Antenna
The antenna consists of 6 segments. The blade is longer than the flagellum. Lauterborn organs alternate on the second and third segment Microt antenna.
Mentum
The mentum has 3 median teeth and 6 pairs of lateral teeth. The central tooth is smaller than the 2 outer teeth. The ventromental plates are narrow and strongly curved about 0.6-0.8x as wide as the mentum.
Labrum
SI is plumose on both sides and labral lamellae a single plate with > 20 distal teeth. The pecten epipharyngis with 3 teeth (Moller Pillot, 1984a).
Mandible
The mandible with a pale dorsal tooth, one apical and 3 inner teeth. The pecten mandibularis is present and seta interna with 4 toothed and plumose branches.
Differential characteristics
The combination of 2-3 mid-mental teeth Microt mentum, alternating Lauterborn organs Microt antenna and the absence of tubules on segment 10 is distinctive for the genus.
M. tarsalis differs from the other Microtendipes by the 3 median mentum teeth, of which the central one is somewhat smaller than the outer pair. M. rydalensis with 3 median mental teeth differs from M. tarsalis by the pecten epipharyngis with only 9 teeth and the blade subequal to the flagellum.