PROFESSOR OF ANATOMY AND PHYSIOLOGY TO THE ROYAL COLLEGE OF SURGEONS IN LONDON; CORRESPONDING MEMBER OF THE INSTITUTE OF FRANCE, ETC. ETC.

LONDON:

PUBLISHED BY SMITH, ELDER AND CO. 65, CORNHILL.

MDCCCXL.

LONDON:

PRINTED BY STEWART AND MURRAY,

OLD BAILEY.

CONTENTS.

Page
GEOLOGICAL INTRODUCTION [3]
TOXODON PLATENSIS, Descriptionof Cranium[16]
of Lower Jaw and Teeth[29]
MACRAUCHENIA PATACHONICA,Cervical Vertebræ[35]
Lumbar Vertebræ[40]
Scapula[43]
Antibrachium and Fore-foot[44]
Femur[48]
Tibia, Astragalus, and Metatarsal Bone[50]
GLOSSOTHERIUM, Fragment of Cranium[57]
MYLODON DARWINII, Lower Jaw and Teeth[63]
SCELIDOTHERIUM LEPTOCEPHALUM,Cranium and Teeth[73]
Vertebral Column[84]
Bones of the Extremities[88]
MEGALONYX JEFFERSONII, Lower Jaw[99]
MEGATHERIUM CUVIERI, Cranium and Teeth[100]
TESSELATED ARMOUR AND BONES, large Edentata[106]
MASTODON ANGUSTIDENS, Cuv. (?)[108]
EQUUS, Molar Teeth[108]
CTENOMYS PRISCUS, and a large Rodent[109]
Geological contemporaneity of preceding extinct Mammalia[111]

LIST OF PLATES.