118 PEACH. ROOT SOW-BUGS. 



the animals under consideration pertain to the order IsopodAjL e„ 

 equal-footed, having fourteen pairs of legs of nearly equal size, 

 and to the family ONisciDiE, which, like other families of this 

 order has four antennae, but here the inner pair of these antennae 

 is quite short and little apparent, consisting at most of only two 

 joints. The typical genus of this family, named Oniscus, by Lin- 

 naeus, is by modern naturalists restricted to those species in which 

 the external antennae have eight joints, the three last joints being 

 much more slender than the others, and the sutures separating 

 them much less distinct than those between the other joints. I 

 have never met with any American species having this number 

 of joints to the antennae. The general Porcellio and Armadillo 

 differ from Oniscus in having the slender terminal portion of the 

 antennae divided into but two joints instead of three, making the 

 number of joints seven in all. 



The genus Armadillo is distinguished from Porcellio, and from 

 Oniscus also, by being destitute of the two conical projecting 

 points or short tail-like processes which we observe at the tip of 

 the abdomen in those genera, and also by having the faculty of 

 rolling itself into a ball, resembling when thus rolled up, a pea 

 or pill, whence they are popularly named pill-millipedes. We 

 have one or more species of these inhabiting the southern part 

 of the State and Long Island, but they do not extend to the 

 neighborhood of my residence, and I have not examined them 

 sufficiently to determine whether they are different from the 

 European species of this genus. 



All the animals of this family which have yet been discovered 

 in the central and northern sections of our State pertain to the 

 genus Porcellio. These crustaceans are everywhere common 

 about the roots of trees, under logs and stones, in the crevices of 

 the foundation walls of our buildings and in our cellars, and they 

 are particularly numerous under any logs or billets of wood 

 which are left in our chip yards. They occur, in short, in all 

 situations that are damp, cool and dark. Frequently, by night 

 in wet weather, they crawl about the rooms in our dwellings. 

 They are perfectly innocent and harmless, subsisting upon decay- 



