1833 _Porcellio pictus_ Brandt and Razteburg (4), p. 78, pl. 12, fig. 5. 1839 _Porcellio melanocephalus_ Koch (34), part 28, pl. XVIII. 1853 _Porcellio melanocephalus_ Schnitzler (65), p. 24. 1856 _Porcellio mixtus_ Fitch (29), p. 120. 1868 _Porcellio pictus_ Bate and Westwood (1), p. 1898 _Porcellio pictus_ Sars (59), p. 177. pl. LXXVII., fig. 1. There are tubercles on the body of _Porcellio pictus_, which is a striking looking animal. Its head is black with the lateral lobes curved outwards; there is a dark band down the middle of the back and commonly two others on each side, with more or less conspicuous yellow markings between. The distal (terminal) joint of the flagellum is but half the length of the proximal one and the last peduncular joint is longer than the two combined. The abdominal appendages--1 and 2--are provided with air-tubes. [Illustration: FIG. 48.--FLAGELLUM AND LAST PEDUNCULAR JOINT OF THE ANTENNA OF _Porcellio pictus_.] _BRITISH LOCALITIES:--_ _England_: Maldon; (W.M.W. from R.M.): Chislehurst; (Bate and Westwood, 1): Cooper's Hill, near Cheltenham; (Norman, 49): Exeter; (Parfitt, 53): Kent; (Bate and Westwood, 1.) _Scotland_: Between Leith and Portobello; (Scott, 68): Cumbrae (Scott, 68a): Ayrshire; (Boyd in Norman, 49): Banff; (T. Edwards in Norman, 49). _Ireland_: Dublin; Belfast; (Bate and Westwood, 1): Galway; Maryborough; Queen's Co., Castel; and Caher Co. Tipperary; (R.F.S.) _FOREIGN DISTRIBUTION:--_ _Europe_: France; (25): North, West-Central, and East Europe; (8): Sweden; Norway; Denmark; Germany; Hungary; Russia; (59). _North America_: (8). =Porcellio dilatatus= Brandt. PLATE XV. 1833 _Porcellio dilatatus_ Brandt and Ratzeburg (4), p. 78, pl. 12., fig. 6. 1840 _Porcellio scaber_ Milne-Edwards (not Latreille) (46), p. 167. 1868 _Porcellio dilatatus_ Bate and Westwood (1), p. 1898 _Porcellio dilatatus_ Sars (59), p. 179, pl. LXXVII., fig. 2. The fact that _Porcellio dilatatus_ is more than half as broad as it is long, at once distinguishes it from the other species of _Porcellio_. It is tuberculated and of somewhat a lighter grey than _Porcellio scaber_ usually is. The two species agree in having the two joints of the flagellum equal, but the last peduncular joint, as in _Porcellio pictus_, is longer than the flagellum. As in the two preceding species, air-tubes are found in the outer plates of the appendages on the first two abdominal segments. _Porcellio dilatatus_ is to be looked for near houses. [Illustration: FIG. 49.--FLAGELLUM AND LAST PEDUNCULAR JOINT OF THE ANTENNA OF _Porcellio dilatatus_.] _BRITISH LOCALITIES:--_ _England_: Maldon; (W.M.W. from R.M.): Eton; (Stebbing from W.M.W., 71a): Berkhamsted; (Norman, 50): Headley, Surrey; Ventnor; (Stebbing in Norman, 49).