PORCELLIO SCABER. 4.77 
spinose at the tip. The foot-jaws are formed of a pair 
of large oblong plates, having an elongated horny sup- 
port on the outside arising from their base. The ex- 
tremity of each is furnished with a number of minute 
teeth, the inner ones arising from a distinct but very 
short lobe or division. 
The terminal appendages of the tail are robust, with 
the outer division triangularly ovate, and extending 
about half its length beyond the extremity of the telson 
or terminal segment of the tail, which ends in a sharp 
triangular point, having a groove along the middle of its 
dorsal surface, and which completely covers and conceals 
the elongated accessory plate of the base of the apical 
appendages. 
The colour of this species is uniformly of a greyish 
black or slaty grey, more or less strongly spotted with 
yellow ochre or whitish buff. A nearly uniform salmon- 
coloured variety also occurs, and it is very probable that 
others of the supposed species figured by Koch may be 
only varieties. 
In P. dubius of Koch, the pale spots are wanting, the 
uniform colour being blackish. In his P. afinis there 
is a pale lateral line parallel to each side, running 
through the’whole of the segments of the body. 
The species runs with agility, and partially rolls itself 
into a ball when alarmed. It has been observed feeding 
on living caterpillars, frequenting moist places where 
decaying vegetation is found, and even among sea-weed, 
in company with Ligia, &c. We have also found it 
partial to growing vegetables, and it appears to possess 
a strong partiality for nearly ripe wall-fruit. It is very 
widely distributed throughout England and Ireland. The 
female may be found with eggs contained in the ventral 
pouch throughout the year. 
