92 



ZOOLOGY. 



wood. The highest Isopods are Idotcea, of which /. irro- 

 iafus is our most abundant species, being common in eel- 

 grass, etc., between and just below tide-mariis. While the 



Fig. 114. — Qaviviarus robustus, from fresh water. Much enlarged. 



Isopods are broad and flat, the Amphipods are compressed, 

 and the back is usually more or less arched. Such is the 



Fig. IK.—Nebiilia hjpes. Enlarged 6 times. 



Gammariis, or beach -flea (Fig. 114), found in salt and fresh 

 water. 



Order 5. PhyVocarida. — This group is represented by a 

 little Crustacean, witli a compressed body, and broad leaf- 



