Subclass (II). DIDELPHIA or METATHERIA. Order. MARSUPIALIA. Suborder (1). POLYPROTODONTIA. Family =Amphitheriidae=. _Phascolotherium._ Family =Didelphyidae=. Didelphys--opossum. Family =Dasyuridae=. Thylacinus--Tasmanian wolf. Sarcophilus--Tasmanian devil. Dasyurus. Family =Peramelidae=. Perameles--bandicoot. Choeropus. Family =Notoryctidae=. Notoryctes--marsupial mole. Suborder (2). DIPROTODONTIA. Family =Phascolomyidae=. Phascolomys--wombat. Family Phalangeridae. Tarsipes. Phalanger--cuscus. Phascolarctus--koala. _Thylacoleo._ Family =Diprotodontidae=. _Diprotodon._ Family =Nototheriidae=. _Nototherium._ Family =Macropodidae=. Macropus--kangaroo. Family =Epanorthidae=. Coenolestes. Subclass (III). MONODELPHIA or EUTHERIA. Order 1. EDENTATA. Family =Bradypodidae=. Bradypus } }--sloths. Choloepus } Family =Megatheriidae=. _Megatherium_--ground sloth. Family =Myrmecophagidae=. Myrmecophaga--great ant-eater. Cycloturus--two-toed ant-eater. Family =Dasypodidae=. Chlamydophorus } Dasypus }--armadillos. Priodon } Tatusia } Family =Glyptodontidae=. _Glyptodon._ Family =Manidae=. Manis--pangolin. Family =Orycteropodidae=. Orycteropus--aard-vark. Order 2. SIRENIA. Family =Manatidae=. Manatus--manatee. Family =Rhytinidae=. _Rhytina_--Steller's sea-cow. Family =Halicoridae=. Halicore--dugong. Family =Halitheriidae=. _Halitherium._ Order 3. CETACEA. Suborder (1). ARCHAEOCETI. Family =Zeuglodontidae=. _Zeuglodon._ Suborder (2). MYSTACOCETI or BALAENOIDEA. Family =Balaenidae=. Balaena--right whale. Megaptera--humpbacked whale. Balaenoptera--rorqual. Suborder (3). ODONTOCETI. Family =Physeteridae=. Physeter--sperm whale. Hyperoödon--bottlenose. Ziphius. Mesoplodon. Family =Physodontidae=. _Physodon._ Family =Squalodontidae=. _Squalodon._ Family =Platanistidae=. Platanista--Gangetic dolphin. Inia. Pontoporia.