Part 1

THE ZOOLOGY OF THE VOYAGE OF H. M. S. BEAGLE, UNDER THE COMMAND OF CAPTAIN FITZROY, R.N., DURING THE YEARS 1832 TO 1836. PUBLISHED WITH THE APPROVAL OF THE LORDS COMMISSIONERS OF HER MAJESTY’S TREASURY.

Edited and Superintended by

CHARLES DARWIN, ESQ. M.A. F.R.S. SEC. G.S.

NATURALIST TO THE EXPEDITION.

PART I.

FOSSIL MAMMALIA:

RICHARD OWEN, ESQ. F.R.S.

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, Description of 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.

PLATE I. Cranium of Toxodon Platensis, nat. size, basal view, with the sixth molar, right side upper jaw, and grinding surface of the seventh molar left side. II. Cranium of Toxodon Platensis, side view. III. Ditto, upper view. IV. Ditto, back view, with two views of the sixth molar, right side, upper jaw. V. Fragment of lower jaw, and teeth of Toxodon Platensis. VI. Cervical vertebræ of the Macrauchenia Patachonica. VII. Ditto, ditto, and of Auchenia Llama. VIII. Lumbar vertebræ of the Macrauchenia Patachonica. a. Medium convex articular surface joining the body of the sacrum. b. Lateral concavities joining the transverse processes of the b. sacrum. c. Ossified ligament of an anchylosed lumbar vertebra. IX. Fig. 1 and 2. Fragments of the Scapula. Fig. 3. Distal end of the femur of Macrauchenia Patachonica. X. Proximal ends of the anchylosed radius and ulna of Macrauchenia Patachonica. XI. Bones of the right fore-foot, Macrauchenia Patachonica. XII. Femur, Macrauchenia Patachonica. XIII. Anchylosed tibia and fibula, Macrauchenia Patachonica. XIV. Right astragalus, Macrauchenia Patachonica. XV. Fig. 1. External metatarsal bone of the right hind-foot. Fig. 2. Proximal end of internal metacarpal bone, right fore-foot. Fig. 3 and 4. Proximal end of middle metacarpal bone. Fig. 5. Proximal end of external metacarpal bone, right fore-foot, Macrauchenia Patachonica. XVI. Fragment of cranium of the Glossotherium. Fig. 1. Side view. Fig. 2. Base view. Fig. 3. Inside view, all half natural size. Fig. 4. Os tympanicum, natural size. XVII. Fig. 1. Megalonyx Jeffersonii. Fig. 2. Megalonyx laqueatus. Fig. 3 and 4. Mylodon Harlani. Fig. 5. Mylodon Darwinii. XVIII. Lower jaw of the Mylodon Darwinii. XIX. Fig. 1. Side view of the lower jaw. Fig. 2 and 3. Last molar tooth. Fig. 4. Front view of the symphysis of the lower jaw, Mylodon Darwinii. XX. Portion of the skeleton of the Scelidotherium leptocephalum. XXI. Fig. 1. Side view of the cranium. Fig. 2. Back view of the cranium. Fig. 3, 4, and 5, anterior molar, upper jaw Scelidotherium. XXII. Upper view of the cranium of the Scelidotherium. XXIII. Fig. 1. Inside view of cranium. Fig. 2. Articular surface for the lower jaw. Fig. 3. Section of upper jaw and molar teeth. Fig. 4. Section of lower jaw and molar teeth, Scelidotherium. XXIV. Cervical and anterior dorsal vertebræ of. Fig. 1. Scelidotherium. Fig. 2. Orycteropus. Fig. 3. Dasypus. Fig. 4. Myrmecophaga jubata; all one-third nat. size. XXV. Fig. 1 and 2. Humerus, radius and ulna of Scelidotherium. Fig. 3. Head of humerus. Fig. 4. Head of radius. Fig. 5, 6, and 7. Femur of Scelidotherium. XXVI. Fig. 1, 3, and 5. Astragalus of Megatherium. Fig. 2, 4, and 6. Astragalus of Scelidotherium. XXVII. Fig. 1 and 2. Patella and head of tibia of Scelidotherium. Fig. 3, 4, and 5. Ungueal phalanx of Scelidotherium. XXVIII. Fig. 1. Astragalus of Megatherium. Fig. 2. Astragalus of Scelidotherium. Fig. 3–6. Astragalus of Mylodon or Megalonyx. XXIX. Lower jaw of Megalonyx Jeffersonii. XXX. Fragment of the Cranium of Megatherium Cuvieri. XXXI. Section of the upper jaw and teeth of the Megatherium Cuvieri. XXXII. Fig. 1. Magnified view of structure of molar of Megatherium. Fig. 2–5. Ungueal phalanx and portions of tesselated armour of Hoplophorus euphractus. Fig. 6–11. Jaws and teeth of Ctenomys priscus. Fig. 12. Bones of right hind-foot of a Rodent. Fig. 13 and 14. Fossil tooth of a Horse.