The terrestrial Isopods (Oniscidea) of the Arabian Peninsula

Seventeen species of terrestrial Isopoda from the Arabian Peninsula are listed. All the species but the cosmopolitan Porcellionides pruinosus (Brandt, 1833) and the littoral Tylos maindroni Giordani Soika, 1954 are illustrated. Four species are described as new: Periscyphis barnardi, P. buettikeri, Somalodillo paeninsulae and Koweitoniscus rostratus. The following synonymies are proposed: Periscyphis chindeensis Barnard, 1932 = P. vittatus Omer-Cooper, 1926; Koweitoniscus ahmadii Vandel, 1975 = K. tamei (Omer-Cooper, 1923). A key for the identification of all the genera and species is given, together with comments on the distribution of the oniscidean fauna of the Arabian Peninsula.