Halacarus Gosse, 1855

AD present, often with an anterior spine. OC and PD often reduced or absent. Most species with five pairs of welldeveloped gp. Adanal setae near gp-5. One dorsal seta and three ventral setae on PE. Females with 2–15 pairs of perigenital setae. Males with up to 150 perigenital setae, often with a few stronger and longer outlying setae. Both sexes with 3–5 pairs of subgenital setae. Gnathosomal base almost square; rostrum parallel sided. Basi- and tritorostral setae on rostrum. Palps four-segmented, laterally attached to gnathosoma. Second palpal segment with two setae; P3 with a spine; P4 with three setae at the basal whorl, one seta at half-length of the segment, and a setula and two spurs at its tip. Leg I longer and stronger than remaining legs, bearing stout spines on tibia, genu and telofemur. Tarsi I with dorsolateral solenidia and a seta-like famulus. Tarsi II with dorsomedial solenidion. Genu I almost as long as tibia I and telofemur I. Two nymphal stages, protonymph and deutonymph, present.