*circulans Gisin, 1952
*laminatipes Bagnall, 1937
Onychiurus ambulans is a common and widespread species found in soil, leaf litter and caves. The largest specimen Steve saw was 2.9 mm in length. The furca is absent and there are two anal spines (Fig. 1) with occasional mutations (Fig. 2). The post-antennal organ has from 11 to 13 complex vesicles. The empodium of the foot is long and filamentous and is about the same length as the claw (Fig. 3). The first thoracic segment has 1+1 dorsal pseudocelli (PSO) (Fig. 4). The typical PSO formula is 32/133/33353. Males (Fig. 5) are easy to identify as they have characteristic groups of specialised setae on the ventral side of abdominal segments 2 and 3 (Fig. 6).
Steve examined more than 200 specimens of Onychiurus ambulans in the NHML collection, including two donated by Sir John Lubbock in the 19th century (collected from Uppsala, Sweden). In some publications it is called Onychiurus circulans, but here we follow the decision of Pomorski (1998) and call it Onychiurus ambulans. Onychiurus laminatipes Bagnall 1937 is a junior synonym of Onychiurus ambulans.
Specimens of Onychiurus 'rectospinatus' and Onychiurus 'subambulans' collected by Bagnall do not correspond to modern descriptions of these species and they should not be included as definite members of the UK and Eire checklist.