TABLE OF CONTENTS. 



Page. 



INTRODUCTION 187 



CLASSIFICATION 189 



Aplacophora 189 



Chaetodermatidae 189 



Chaetoderma 190 



Neomeniidae 191 



Neomenia 191 



Proneomeniidae 191 



Proneomenia 191 



Dorymenia 192 



Strophomenia 192 



Dondersiidae 192 



Nierstrassia 193 



DESCRIPTION OF SPECIES . . . 193 ' 



Chaetoderma nitidulum 193 



Pace. 



Chaetoderma caudatum 193 



C. vadorum 195 



C. lucidum 198 



C. bacillmn 201 



C. squamosum 204 



Neomenia verrilU 206 



Proneomenia acuminata 215 



Dorymenia peroneopsis 222 



Strophomenia agassizi 229 



Nierstrassia fragile 235 



EMBRYOLOGY 240 



GENERAL CONSIDERATIONS . . . 251 



BIBLIOGRAPHY 261 



EXPLANATION OF PLATES ... 203 



