286 COMPARATIVE ZOOLOGY. 



Wood-louse, or Sow-bug (Oniscus), so common in damp 

 places, the Slaters (Idotea), and the Sand-fleas (Gammarm), 

 seen by the sea-side. 



4. Decapods, having ten legs, as the Shrimp (Crangori), 



Fig. 256.— Lobster (Homarus vulgaris). 



Fig. 257.— Swimming Crab (Platyony chits). 



