234 ELEMENTS OF COMPARATIVE ZOOLOGY. 



moist places, where they feed upon decaying vegetable 

 matter. They are harmless forms, but several species se- 



FIG. 111. A Diplopod (Spirostrephon), showing the two legs to a segment. 

 From Packard. 



crete a strong-smelling substance, which protects them 

 against their foes. 



