(Panzer, 1813)
Body
Large larvae up to 12 mm long. The parapods are separate and bear rows of claws. Procercus and two pairs of anal tubules present (Wiederholm, 1983; Moller Pillot, 1984b).
Head
The head length is 0.6 mm (Murray and Ashe, 1981).
Antenna
The antenna consists of four segments. The blade is shorter than segment 2. Lauterborn organs are absent.
Mentum
The mentum has one median tooth and 6 pairs of lateral teeth. The ventromental plates are inconspicuous or absent. The beard is absent Eury cras mentum.
Labrum
The pecten epipharyngis consists of three broad triangular scales, SI is simpel and the premandible has two apical teeth (Wiederholm, 1983).
Mandible
The mandible has an apical tooth and 4 inner teeth. The seta interna present (Wiederholm, 1983).
Differential characteristics
The following combination separates Eurycnemus from all other Orthocladiinae except Corynoneura: antenna with 4 segments, mentum with 6 pairs of lateral teeth Eury cras mentum and mandible with 4 inner teeth. Eurycnemus is easily separated from Corynoneura in having a normal antenna instead of an antenna as long as the length of the head Coryno antenna.