_Family_ DIDELPHYIDÆ, 133; _Chironectes_, 134; _Didelphys_, 135. _Family_ DASYURIDÆ, 136; _Subfamily_ Dasyurinæ, 136; _Thylacinus_, 136; _Sarcophilus_, 137; _Dasyurus_, 138; _Phascologale_, 139; _Sminthopsis_, 139; _Antechinomys_, 139; _Subfamily_ Myrmecobiinæ, 140; _Myrmecobius_, 140. _Family_ PERAMELIDÆ, 141; _Perameles_, 142; _Peragale_, 143; _Chœropus_, 143. _Suborder_ DIPROTODONTIA 144 _Family_ PHASCOLOMYIDÆ, 144; _Phascolomys_, 145; _Phascolonus_, 146. _Family_ PHALANGERIDÆ, 147; _Subfamily_ Tarsipedinæ, 148; _Tarsipes_, 148; _Subfamily_ Phalangerinæ, 149; _Phalanger_, 149; _Trichosurus_, 150; _Pseudochirus_, 151; _Petauroides_, 152; _Dactylopsila_, 152; _Petaurus_, 153; _Gymnobelideus_, 154; _Dromicia_, 154; _Distœchurus_, 155; _Acrobates_, 155; _Subfamily_ Phascolarctinæ, 155; _Phascolarctus_, 156. EXTINCT PHALANGEROIDS, 157; _Thylacoleo_, 157. _Family_ MACROPODIDÆ, 158; _Subfamily_ Hypsiprymnodontinæ, 162; _Hypsiprymnodon_, 162; _Triclis_, 162; _Subfamily_ Potoroinæ, 162; _Potorous_, 163; _Bettongia_, 163; _Caloprymnus_, 164; _Æpyprymnus_, 164; _Subfamily_ Macropodinæ, 164; _Lagostrophus_, 165; _Dendrolagus_, 165; _Dorcopsis_, 166; _Lagorchestes_, 166; _Onychogale_, 166; _Petrogale_, 167; _Macropus_, 167; Extinct genera, 170. EXTINCT FAMILIES, 171; _Diprotodon_, 171; _Nototherium_, 171. CHAPTER VII THE SUBCLASS EUTHERIA AND THE ORDER EDENTATA 173 General characters and classification of Eutheria, 173. ORDER EDENTATA 176 _Family_ BRADYPODIDÆ, 179; _Bradypus_, 181; _Cholœpus_, 182; _Nothropus_, 183. _Family_ MEGATHERIIDÆ, 183; _Megatherium_, 185; _Scelidotherium_ and _Mylodon_, 188; _Promegatherium_, 189. _Family_ MYRMECOPHAGIDÆ, 190; _Myrmecophaga_, 190; _Tamandua_, 192; _Cycloturus_, 193. _Family_ DASYPODIDÆ, 194; _Subfamily_ Chlamydophorinæ, 196; _Chlamydophorus_, 196; _Subfamily_ Dasypodinæ, 197; _Dasypus_, 197; _Xenurus_, 198; _Priodon_, 198; _Tolypeutes_, 199; _Subfamily_ Tatusiinæ, 200; _Tatusia_, 200; Extinct genera, 201. _Family_ GLYPTODONTIDÆ, 202. _Family_ MANIDÆ, 204; _Manis_, 204; _Palæomanis_, 208. _Family_ ORYCTEROPODIDÆ, 208; _Orycteropus_, 208. Bibliography, 211. CHAPTER VIII THE ORDERS SIRENIA AND CETACEA 212 ORDER SIRENIA 212