Hypogastrura burkilli is a member of the difficult group of Hypogastrura with three or four clavate tenant setae in two whorls (A and B) on the tibiotarsus of the third leg (tt3). Hypogastrura burkilli has tt1 with one clavate tenant seta in the A row (the one nearest the claw) and one clavate tenant seta in the B row (Fig. 1), tt2 with one clavate tenant seta in the A row and two clavate tenant setae in the B row (Fig. 2), and tt3 with one clavate tenant seta in the A row and two clavate tenant setae in the B row (the three setae on tt3 arranged in a tight triangle; Fig. 3). The abdominal setae are of similar length (macrosetae not present; Fig. 4). Specimens of Hypogastrura burkilli resemble very large Hypogastrura purpurescens (the biggest I have seen was 2.8 mm in length). The material in the NHML collection is in rather poor condition but the arrangement of clavate setae on tt3 is clear in specimens from Boxhill and Effingham in Surrey collected from under bark. However, more work is required to clarify the species boundaries in this group.
Fig. 1 (above) : Tibiotarsus of first leg of Hypogastrura burkilli collected from Effingham, Surrey in July 1934 by R.S. Bagnall. There is one clavate tenant seta in the A row (ts A1) and one clavate tenant setae in the B row (ts B1).
Fig. 2 (above) : Tibiotarsus of second leg of the of the same specimen of H. burkilli shown in Fig. 1. There is one clavate tenant seta in the A row (ts A1) and two clavate tenant setae in the B row (ts B1 and ts B2).
Fig. 3 (above) : Tibiotarsus of third leg of the of the same specimen of H. burkilli shown in Fig. 1. There is one clavate tenant seta in the A row (ts A1) and two clavate tenant setae in the B row (ts B1 and ts B2).
Fig. 4 (above) : Posterior abdomen of the same specimen of H. burkilli shown in Fig. 1. The abdominal setae are all of similar length; as, anal spines.
