CHAPTER II.

FREE MESSMATES.

Found in all Classes--Fierasfers in Holothuridæ--Pilot Fish--Remora--Crustacean Messmates--Poisoning by Mussels--Pearl Mussel and small Crab--Dromiæ--Turtle Crabs--Macrourous Decapods--Hermit Crabs--Friendship of Pagurus and Anemone--Isopods--Messmates on Whales-- Molluscan Messmates--Lerneans--Distomes--Messmates of the Echinodermata--Of Sponges--Infusorial Messmates 4