Antenna short and stout, with 4 or 5 segments, some with annulated segment 3; comparatively short and stout. Ring organ situated in the lower 1/2 of basal segment.
Labrum with SIII large, of the same size and form as SI and SII, but without tubercle; SIVA on a very high tubercle, as long as that of SII. Pecten epipharyngis compact, consisting of 3 basally-fused spines.
Mandible with 5 teeth on inner margin.
Mentum with median tooth forming the apex of anterior margin; 7 pairs of lateral teeth present; first and second short, third much longer, the rest short, decreasing in size laterally.
Body with very weak body setae; procercus unicoloured, either hyaline or black all over; with a brush of 7-8 moderate length, slender, apical setae. Posterior parapods slender.
The immature stages of Parochlus live in running waters of various types. Numerous species occur in the southern temperate zone, with some 30 species in temperate South America and the Andes, four in s.e. Australia, ten in New Zealand. Most species are distinguished by their pupae - few larval associations have been made. In the Holarctic region, only P. kiefferi occurs.