CONTENTS. 



P. 



Introduction 5 



Systematic Section 7 



Opisthobranchia 7 



Synopsis of Families 7 



Synopsis of Genera and Species 10 



Pteropoda 38 



Synopsis of Families 38 



Synopsis of Genera and Species . . 38 



Geographical and Bathymetrical Distribution 40 



Description of New Forms 97 



List of Works referred to 103 



Index 108 



Explanation of the Plates 113 



