Vi CONTENTS. 



Platyhelminthes (Continued). Page. 



Nemertinea 44 



Tetrastemrna 44 



NEMATHELMINTHES 46 



Asoaris 46 



Trichina 47 



TROCHELMINTHES 48 



ROTIFERA 48 



Brachionus (A Rotifer) 48 



MOLLUSCOIDA 50 



POLYZOA 50 



Bugula 50 



Plumatella 52 



Brachiopoda 52 



Terebratulina 52 



ECHINODERMATA 54 



ASTEROIDEA 55 



Asterias (Starfish) 55 



Ophiuroidea 60 



Ophiura (Serpent-Star) 60 



ECHINOIDEA 61 



Arbacia (Sea-Urchin) 61 



HOLOTHUROIDEA 67 



Thyone (Sea-Cucumbei ) 67 



ANNELIDA 70 



Ch.etopoda 71 



Nereis virens (Clam-Worm) 71 



Lumbricus (Earthworm) 74 



Autolytus cornutus 80 



Lepidonotiis squamatus 81 



Diopatra cuprea 81 



Chsetopterus 82 



Amphitrite ornata 83 



Cistenides gouldii 84 



Clymenella torquata ... •. 84 



Arenicola cristata 85 



Sabella microthalma 85 



Hydroides 86 



Spirorbis borealis 86 



Gephyrea 86 



Phascolosoma 86 



MOLLUSCA 89 



Lamellibranciiiata 91 



Venus mercenaria (Quohog) 91 



Yoldia hmatula 99 



Mytilus or Modiola (Mussels) 100 



Pecten irradians (Scallop) 101 



Ostrea virginiana (Oyster) 103 



Solenomya 103 



Mya arenaria (Long Clam) 104 



Ensis directus (Razor-shell Clam) 105 



