The mapped records are for slides labelled 'Odontella sp.', 'Odontella stachi', and 'Odontella empodialis' in the NHML collection. The only species described by Fjellberg (1998) was Odontella lamellifera; in view of his comments regarding the variability of some of the diagnostic characters used by Gisin (1960) to separate Odontella species, I have decided to map all members of this genus recorded from England and Wales as Odontella lamellifera 'group' until the species boundaries can be clarified. There are no records of Odontella from Ireland or Scotland. These bluish-grey animals should be looked for in leaf litter and under tree bark. The longest UK specimen I have seen was 1.3 mm in length. There are five ocelli in each eye, and a small post-antennal organ is present (Fig. 1). The empodium on the foot is either absent (Fig. 2) or extremely small and the mucro has two dorsal lobes (Fig. 3). There are two small anal spines at the tip of the abdomen (Fig. 4).
Fig. 1 (above): Post-antennal organ (PAO) and ocelli (1-5) of Odontella lamellifera collected from Roudsea Wood, Lancashire in September 1962 by Peter Lawrence.
Fig. 2 (above): Foot of the first leg of the same specimen of Odontella lamellifera shown in Fig. 1. The empodium is extremely small, or absent altogether as in this example.
Fig. 3 (above): Furca of the same specimen of Odontella lamellifera shown in Fig. 1. The mucro is highly distinctive with two dorsal lobes. man, manubrium; mgp, male genital plate on the ventral side of the fifth abdominal segment.
Fig. 4 (above): Tiny anal spines (*) of the same specimen of Odontella lamellifera shown in Fig. 1.
