Strenzke, 1950
Body
Small larvae up to 5 mm long. Living larvae transparent with visible tracheal stems. The anterior and posterior parapods are separate and bear rows of claws. Anterior parapods with large combs Paraphaen pseudirr. ant pod 8. The anal segment is placed ventrally on the preanal segment, thus forming an angle with the body axis. The procercus is very small, two pairs of anal tubules are more than 2 x as long as the posterior parapods (Wiederholm, 1983; Moller Pillot, 1984b; Saether and Wang, 1995).
Head
The head length is 0.25 - 0.32 mm. The smaller eye is placed ventrally of the larger one instead of distally Paraphaenocladius eye.
Antenna
The antenna consists of five segments, segment 3 shorter than segment 4. The blade is about as long as the flagellum. Lauterborn organs very large Parapha pseudirr antenna9.
Mentum
The mentum has one median tooth and 5 pairs of lateral teeth. The median tooth is dome shaped. The ventromental plates are triangular and do not cover teeth of the mentum Parapha pseudirr mentum 8. The beard is absent. The setae submenti are close to the mentum.
Labrum
The pecten epipharyngis consists of three short spines, SI is plumose and the labral lamellae are fused to form a plate with a smooth of serrated tip. The premandible has three apical teeth (Wiederholm, 1983; Moller Pillot, 1984b).
Mandible
The mandible has an apical tooth and 3 inner teeth. (Wiederholm, 1983).
Differential characteristics
The combination of two eyes on top of each other and the more or less right angle between the anal segment and the body axis are distinctive.
P. pseudirritus can be separated from the other Paraphaenocladius by the combs on the anterior parapods, also the triangular ventromental plates are distinctive.