LIST OF CONTENTS. 



PAGE. 

 PROTOZOA. 



Amoeba 3 



Paramcecium 5 



Vorticella 9 



PORIFERA. 



A Marine Sponge (Grantia sp.) II 



CCELENTERATA. 



The Fresh-water Hydra 15 



A Hydroid (Pennaria tiarella) 19 



A Hydroid Medusa (Gonionemus vertens) 23 



PLATYHELMINTHES. 



A Flat Worm (Planaria) 25 



A Tapeworm (Tania sp.) 27 



TROCHELMINTHES. 



A Rotifer (Wheel animalcule) 31 



MOLLUSCOIDA. 



Bugula turrita (A Sea-mat] 35 



ECHINODERMATA. 



A Starfish (Asterias vulgaris) 39 



ANNULATA. 



An Earthworm (Lumbricus terrestris] 45 



ARTHROPODA. 



A Water-flea (Cyclops) 49 



A Lobster or a Crayfish 53 



A Centiped (Scolopendra heros) 61 



A Grasshopper (Melanoplus differ entialis) 65 



A Spider 73 



v 



