Terrestrial isopods of the genus Porcellio Latreille, 1804 (Isopoda; Oniscidea) in Iran, with a description of a new species Kashani, Ghasem M. Ahdiyeh, Abedini Zahra, Hatami Zootaxa 2017 4311 1 129 136 7PTS4 Latreille, 1804 Latreille 1804 [238,535,293,319] Malacostraca Porcellionidae Porcellio Animalia Isopoda 1 130 Arthropoda genus   Type species:  Porcellio scaberLatreille, 1804   Diagnosis.A member of the genus  Porcelliocan be diagnosed by the enlarged pleon-epimera constituting continuous outline with the pereon; pereon-epimera I with cocave posterolateral margins; head with welldeveloped lateral lobes; eyes with more than 20 ommatidia; telson triangular with concave lateral margins; pleopod exopodites I–II with monospiracular covered lungs and no conglobation ability ( Schmalfuss & Ferrara 1978, Schmalfuss 1992).   Remarks.The genus  Porcelliois a large taxonomic group that cannot be defined by a single character. Indeed, none of the above mentioned features satisfactorily diagnose the genus ( Schmalfuss 1992). Schmalfuss (1998)considered  Porcellioas a paraphyletic group including two different linages that have been united due to convergent evolution. According to him, “the north African laevis-hoffmannseggi-group defined by elongated male pleopod exopodites, probably should be considered a separate genus which then must be called RogopusBudde- Lund, 1908”. The northern Mediterranean scaber-obsolotus-group is diagnosed by short pleopod exopodites that includes also west Asian species ( Schmalfuss 1992). Obviously, a revision of the genus  Porcelliois required to be divided to more natural genera.