1804 _Porcellio laevis_ Latreille (37), p. 46. 1827 _Porcellio degeerii_ Savigny and Audouin (61), p. 289. 1833 _Porcellio cucercus_ Brandt (3), p. 177. 1833 _Porcellio syriacus_ Brandt (3), p. 178. 1833 _Porcellio musculus_ Brandt (3), p. 180. 1833 _Porcellio cinerascens_ Brandt (3), p. 178. 1833 _Porcellio dubius_ Brandt (3), p. 178. 1837 _Porcellio poeyi_ Guérin (30), p. 6. 1844 _Porcellio urbicus_ Koch (34), part 36, pl. IV. 1847 _Porcellio flavipes_ Koch (35), p. 206, pl. VIII., fig. 97. 1853 _Cylisticus laevis_ Schnitzler (65), p. 25. 1857 _Porcellio cubensis_ Saussure (60), p. 307. 1857 _Porcellio sumichtasli_ Saussure (60), p. 307. 1857 _Porcellio cotillæ_ Saussure (60), p. 307. 1857 _Porcellio aztecus_ Saussure (60), p. 307. 1857 _Porcellio mexicanus_ Saussure (60), p. 307. Another smooth species is _Porcellio laevis_. The colour of its body is light grey with irregular white markings. The large size of this species and the very long tail-appendages of the males are features which will help to identify it. The distal joint of the flagellum is slightly the longer and as in the last species (_P. rathkei_) the flagellum is equal in length to the last joint of the peduncle. The chief habitats for this species are among vegetable rubbish near human dwellings. Only the first two abdominal appendages contain air-tubes. [Illustration: FIG. 51.--FLAGELLUM AND LAST PEDUNCULAR JOINT OF THE ANTENNA OF _Porcellio laevis_.] _BRITISH LOCALITIES:--_ _England_: Maldon; (W.M.W. from R.M.): Ipswich (1892); Hanwell; Wimbledon; (W.M.W.): Kent; (Kinahan, 32). _Ireland_: Dublin; (Bate and Westwood, 1): Blackrock Dundrum; Co. Dublin; Galway; (R.F.S.) _FOREIGN DISTRIBUTION:--_ _Europe_: France; (25): Spain; (15): Sicily; (19): Hertzogovania; (22): Sweden; Denmark; Germany; Belgium; Austria; Italy; Dalmatia; Greece; Turkey; (59); Corfu; (B.M.): Inca, Majorca (23); (B.M.--Pocock and Thomas.) _Asia_: Syria; Turkestan; (21). _Africa_: Morocco; Algeria; Tunis; Tripoli; Senegal; Egypt; (23). _Atlantic Isles_: Bermudas; Azores; Canaries; Cape Vera; Madeira; (24). _America_: North America; Mexico; Peru; Brazil; Chili; West Indies; Pacific Islands; (59); Sandwich Isles; (B.M.) =Porcellio ratzeburgii= Brandt. PLATE XVIII. 1833 _Porcellio ratzeburgii_ Brandt, (3), p. 178. 1839 _Porcellio nemorensis_ Koch (34), part 28, pl. XIX. 1839 _Porcellio lugubris_ Koch (34), part 28, pl. XX. 1853 _Porcellio quercum_ Schnitzler (65), p. 24. 1898 _Porcellio ratzeburgii_ Sars (59), p. 182, pl. LXXX, fig. 1.