Observations on two woodlouse species (Isopoda; Oniscidea) new to North Wales: Metatrichoniscoides celticus Oliver & Trew, 1981 and Philoscia affinis Verhoeff, 1908

The terrestrial woodlice Metatrichoniscoides celticus Oliver & Trew, 1981 and Philoscia affinis Verhoeff, 1908 are reported as new to North Wales. M. celticus is recorded at its 5th confirmed location in Britain from heathland surrounding Mariandyrys NNR, Anglesey. All previously known records of this elusive endemic are restricted to the south coast of Wales. P. affinis is also recorded at its 7th British site in woodland on Roman Camp, Bangor, Gwynedd, after being discovered new to Britain in 2017. A description with illustrations is provided for both, as well as an updated discussion of habitat preferences based on these new observations.