Metaphorura affinis is a relatively large member of the Subfamily Tullbergiinae. The longest specimen I have seen was 1.3 mm in length and was collected by Bagnall near Hoods Ferry, Co. Antrim in 1939 (as the junior synonym Metaphorura boerneri described by Bagnall in 1936 under which name most of the records have been made). The species is white, blind and possesses an elliptical post-antennal organ with about 20 to 25 simple lobes (Fig. 1). There is a tiny needle-shaped empodium on the foot. The most characteristic feature is the presence of a small conical projection on the sixth abdominal segment (abd6) ventral to the two anal spines (Figs. 3 and 4). Metaphorura affinis appears to be quite widely distributed in soil.
Fig. 1 (above): Post-antennal organs (PAO) on the dorsal side of the anterior region of the head of Metaphorura affinis collected from Cefn, Wales by W.M. Davies (date not known).
Fig. 3 (above): Sixth abdominal segment (abd6) of Metaphorura affinis collected from Bangor West, Ireland in July 1936 by Bagnall. as, anal spines; P, prominent projection.
Fig. 2 (above): Foot of the second leg of the same specimen of Metaphorura affinis shown in Fig. 1.
Fig. 4 (above): Sixth abdominal segment (abd6) of Metaphorura affinis collected from South Queensferry near Edinburgh in March 1937 by Bagnall. as, anal spines; P, prominent projection.
