Head broadly triangular or slender, parallel-sided.
Antenna short and stout, with 5 segments, without annulated segment 3. Ring organ situated in the lower 1/2 of basal segment.
Labrum with SI, SII and SIVA large on pedestals, SIII without pedestal. Pecten epipharyngis with 3 lobes.
Mandible with 5-6 teeth on inner margin.
Mentum with 5 median teeth forming an even apex; 5-6 pairs of lateral teeth present, evenly decreasing in size.
Body either with stout abdomen, with deep constrictions between segments, with weak body setae, very stout posterior parapods directed straight laterad with stout, strongly sclerotised procerci with compact brush of strong apical setae - or - with slender abdomen, scarcely constricted between strongly setose segments, slender parapods and procerci with apical bunch of fine setae. Procerci always dark all over, relatively stout, highly variable in length, with 7 stout apical setae.