Animal Parasites and Messmates

abdomen abode amphipod animals annelids appearance attached birds blood body Bothriocephalus branchial branchial cavity Caligi carapace cavity cercaria cestode cirrhipedes Claparède coast colony colour crab crustaceans curious cysticerci cysticercus damp earth decapod digestive distome echinoderm eggs embryos enclosed establish female fish flea free messmates gasteropod genus gives lodging harbours hatched hooks host ichneumons infested inhabit insects instal interior intestines isopod kind known larva larvæ leeches Lernæans Leuckart live lobster male manner medusa mention messmates microscopic midst molluscs Mons mother mouth Müller naturalists neighbour nematode nourishment observed organs pagurus parasites pass Peltogaster pinnotheres polyps present prey produce Prof Professor Semper progeny remarkable resemble scolex seek sexes sexual shell shelter singular skin sometimes species spicules sponge stomach Strongylus sucker tænia tæniæ Tania tape-worm trematode trichinæ tube usually whale worms young