CONTENTS. Vii 



Actaonida d'Orb. . ' . . . . . . . . . 343 



Bullida Pilsbry ........... 245 



CRUSTACEA 247 



ClRRIPEDIA 247 



Lepadidce Darw. ........... 247 



Verrucidce Darw. .......... 248 



Balanida Darw. . . . . . . . . . 249 



DECAPODA . . . . . . . . . . . . . 255 



Carcinoplacidtz Ortmann . . . . . . . . . 255 



LIST OF FOSSILS DESCRIBED . 256 



GENERAL CONSIDERATIONS 260 



THE PATAGONJAN BEDS ........... 260 



IDENTITY OF PATAGONIAN AND SUPRAPATAGONIAN BEDS ...... 265 



THE AGE OF THE PATAGONIAN BEDS 286 



THE MAGELLANIAN BEDS ........... 303 



THE CAPE FAIRWEATHER BEDS (? MARINE TEHUELCHE BEDS) .... 307 



ORIGIN AND DEVELOPMENT OF THE PATAGONIAN MARINE FAUNAS . . . . 310 



1. THEORY OF ANTARCTICA .......... 310 



2. RELATIONS OF THE PATAGONIAN DEPOSITS TO OTHER PARTS OF SOUTH AMERICA 



AND TO THE REST OF THE WORLD : THEORY OF " ARCHIPLATA " AND 



" ARCHHELENIS ". .......... 319 



BIBLIOGRAPHY 325 



PART III. MAMMALIA OF THE SANTA CRUZ BEDS. 



MARSUPIALIA. 



BY W. J. SINCLAIR. 



INTRODUCTION 333 



CLASSIFICATION OF THE SANTA CRUZ MARSUPIALS .... 334 



POLYPROTODONTIA . . 34 1 



THYLACYNID^J ............ 341 



Borhycena Amegh. .......... 347 



Prothylacynus Amegh. ......... 362 



Cladosictis Amegh. .......... 376 



Amphiproviverra Amegh. ....... 394 



RELATIONSHIPS OF THE THYLACYNID^E ......... 406 



DlDELPHYID/E ............ 



Microbiothcrium Amegh. ........ 



DIPROTODONTIA 416 



C^ENOLESTID^E ......... 4'6 



CMNOLESTIN& ........ 4 I 9 



Halmarliiphus Amegh. . . . . . 4 J 9 



Garzonia Amegh. ...... 4 22 



PAL&OTHENTIN& . ....... 425 



