(Kieffer, 1924)
Body
Medium sized larvae up to 9 mm long. Living larvae may have a greenish thorax and a white abdomen. The anterior and posterior parapods are separate and bear rows of claws. The anal segment is caudal to the preanal segment not making a right angle with the body axis. Procercus and two pairs of anal tubules present (Wiederholm, 1983; Moller Pillot, 1984b).
Head
The head length is 0.27-0.37 mm (Moller Pillot, 1984b).
Antenna
The antenna consists of five segments. Segment 4 may be (much) longer than segment 3. The blade is subequal to or longer than the flagellum. Lauterborn organs are conspicuous Parametr styl antenna.
Mentum
The mentum has two broad median teeth and 5 pairs of lateral teeth. The base of the ventromental plates is U shaped with a distinct darker chitinous swelling in its lowest part. The beard is absent and the setae submenti are arising close to the mentum Parametr styl mentum.
Labrum
The pecten epipharyngis consists of three short spines, SI is plumose. The sclerotized labral lamellae between the SI are weakly sclerotized Parametr styl labrum and the premandible has 2 apical teeth (Wiederholm, 1983; Moller Pillot, 1984b).
Mandible
The mandible has an apical tooth and 3 inner teeth. The seta interna has branches (Wiederholm, 1983).
Differential characteristics
The mentum with the U shaped ventromental plates is distinctive Parametr styl mentum. The combination of a mentum with 2 median and 5 pairs of lateral teeth, weak ventromental plates, labral lamellae present, mandible with 3 inner teeth and the 5-segmented antenna Parametr styl antenna separates the Genus Parametriocnemus from all other genera in the Orthocladiinae.