C N T E N T 8 . 



SYNOPSIS OF THE CLASSES ... 



EXPLANATION OF THE TERMS USED 



EXPLANATION OF THE PLATE 



KEY TO THE FAMILIES 



CEPHALOPODA 



PTEEOPODA 



HETEBOPODA 



GASTEROPODA 



LAMELLIBRANCHIATA 



BRACHIOPODA 



POLYZOA 



TUNICATA 



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