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may think that they have a close relationship. They really belong 
to quite different classes, and the large class containing the Spider’s 
Mites and Scorpions are placed between them; neither however are 
insects, as it is popularly supposed that they are. 
The Woodlice belong to the crustacea, the class which also 
contains the lobsters, crabs, shrimps, &c. The Centipedes and 
Snake Millipedes to the Myriapoda, so they are by no means closely 
allied, although they do bear some resemblance to one another. 
The Woodlice are placed in the order Isopoda, so called because 
their feet are of uniform size; many members of this order are 
aquatic. The terrestial ones, which are commonly known as 
Woodlice, Sowbugs, or Slaters, are divided into six genera, which 
together contain about 17 species. They all bear a great 
resemblance to one another, but differ in various slight particulars ; 
some species have the power of rolling themselves up into a ball, 
when disturbed, others have not. This habit is not confined to the 
members of one genus, for in more than one, some species roll 
themselves up, others cannot. A very common, and I suppose our 
largest species, (Armadillo Vulgaris), when rolled up forms a 
perfect sphere, all its legs and antenne being completely hidden 
beneath its scaly jointed covering. Woodlice are most frequently 
found under rubbish, boards, stones, &c., which have lain on the 
ground for some time. 
One very small species, which measures only one eighth of an 
inch in length, (Platyarthus Hoffmanseggii) (the length of its name 
will make up for its want of size), is quite white, and perfectly 
blind ; it is found not unfrequently in ants’ nests. According to 
Sir John Lubbock, the ants do not take the slightest notice of 
them, though it is certain they sanction their presence, or they 
would kill them, for all unauthorised interlopers are at once 
killed. Sir John suggests that these woodlice may act as scavengers. 
This species 1 believe is only found in ants’ nests. At one time 
woodlice were supposed to be possessed of considerable medicinal 
virtue ; ‘‘ Wine of millipedes,” which was considered a medicine of 
great value, in certain complaints of the liver and kidneys, was 
compounded of crushed woodlice infused in wine. The body of a 
woodlouse is composed of thirteen joints, the first seven of which 
bear legs, the legs are composed of six joints, and terminate in a 
single claw. Beneath the six joints which are not provided with 
legs is placed the breathing apparatus, which consists of branchie. 
They are protected by plates which fold over them. The head is 
furnished with a pair of small compound eyes, and two pairs of 
antenne ; one pair, however, is very small, consisting of three or 
four minute joints; the other is of considerable length, and each 
antennee is composed of 7 or 8 joints. The structure of the mouth 
