(Kieffer, 1913)
Body
Small larvae up to 5 mm long with brown thoracic striations. The L4 body setae are simpel and half as long as the length of the segment. The anterior and posterior parapods are separate and bear rows of claws. Procercus with a strong apical and a smaller basal spur and two pairs of very long anal tubules present Paracric niger anal segments (Wiederholm, 1983).
Head
Antenna
The antenna consists of five segments. The blade is shorter than the flagellum. Lauterborn organs are conspicuous.
Mentum
The mentum has one median tooth and 5 pairs of lateral teeth. The ventromental plates are long. The beard is absent Paracric niger mentum.
Labrum
The pecten epipharyngis consists of three broad pointed scales, SI is simpel sometimes with small apical serrations and the premandible has one apical tooth (Wiederholm, 1983).
Mandible
The mandible has an apical tooth and 3 inner teeth. The seta interna has plumose branches (Wiederholm, 1983).
Differential characteristics
The long body setae and the spurs on the procercus differentiate Paracricotopus from all other Orthacladiinae.