Pseudoscorpiones (Pseudoscorpions)

Atemnidae lack a venom apparatus from the moveable chelal finger.

Carapacal metazone present; pedal femora and patellae I-IV fused.

Tarsi with proximal raised slit sensillum; venom apparatus absent from or substantially reduced in fixed chelal finger; chelal fingers usually with at least one accessory tooth; male genitalia of 'chernetid' type.

Pedipalps raptorial; median maxillary lyrifissure absent; Cheliceral flagellum consists of a single blade; anterior margin of carapace with 2 or more medial lobes; carapace and tergite I with unusual articulation joint; spiracles fused to sternites IV and V.

Stigmatic helix absent; carapce traingular, four eyes on mound removed from anterior border, maxilla without shoulder.

Four eyes near anterior border, fixed finger with four internal trichobothria.

Fixed chelal finger with pit-like structures on external margin; cheliceral flagellum of single blade, without spinules.

Femora of legs I and II with basi-dorsal mound surmounted by a small seta and slit sensilla; setae of female anterior genital operculum extremely small; the pedipalpal femur with 2–3 stout setae on the retrolateral-basal margin.

Carapace subrectangular; eyes near anterior margin; adults with 8 (rarely 7) trichobothria on fixed chelal finger, including three on internal face

Extensive pseudosternum present.