Remains of Cetacea are first met with in Australian rocks in the Oligocene (Balcombian) of Victoria. At Muddy Creek near Hamilton fragments of ribs and other bones of cetacea, not yet determined, occur in the tenacious blue clays of the lower part of the Clifton Bank section. In Australia and New Zealand the oldest determinable remains of this order belong to the Odontoceti, members of which range from Miocene to Pliocene. Teeth of the toothed whales like _Squalodon_ of the Miocene of France and Bavaria have been found in New Zealand (_Kekenodon_); in South Australia (_Metasqualodon_); and in Victoria (_Parasqualodon_). In Victoria the teeth of Squalodontidae occur in the Janjukian beds of Cape Otway, Waurn Ponds and Torquay, represented by molars and anterior teeth of _Parasqualodon wilkinsoni_ (Fig. 142 B, C). The same species also occurs at Table Cape, Tasmania, in beds of similar age. Teeth of _Metasqualodon harwoodi_ (Fig. 142 D) occasionally occur in the white polyzoal rock of the Mount Gambier district, South Australia. The gigantic toothed whale, _Kekenodon onamata_ (Fig. 142 E) occurs in the Marawhenua Greensands (Oamaru Series) at Waitaki Valley, Waihao, Ngapara, Waikouaiti and Milburn in New Zealand. The molar teeth of this striking species, with their serrated crowns, measure nearly five inches in length. =Ear-bones of Whales.--= The tympanic bones of whales are not uncommon in the Janjukian beds of Waurn Ponds, near Geelong, Victoria; and they are occasionally found in the basement bed of the Kalimnan at Beaumaris, Port Phillip. In the absence of any distinctive generic characters they have been referred to the quasi-genus _Cetotolithes_ (Fig. 142 F). McCoy has expressed the opinion that they may perhaps be referable to the ziphioid or beaked whales, for undoubted remains of that group, as teeth of _Ziphius geelongensis_, occur in these same beds; as well as portions of their rostrate crania, in the Kalimnan basement beds at Grange Burn, near Hamilton. The large curved and flattened teeth of _Ziphius (Dolichodon) geelongensis_ are occasionally found, more or less fragmentary, in the polyzoal rock of Waurn Ponds. [Illustration: =Fig. 149.--Tooth of Scaldicetus macgeei, Chapm.= An Extinct Sperm Whale. From the Kalimnan beds of Beaumaris, Port Phillip, Victoria. About 3/4 nat. size.] =Kalimnan-Scaldicetus.--= From the Kalimnan Series (Lower Pliocene) of Beaumaris, Port Phillip, there was described a short time since, a remarkably well preserved specimen of _Scaldicetus_ tooth belonging to a new form, _S. macgeei_ (Fig. 148). Another species of the genus, with teeth of a slender form, has been found in the same geological series, at Grange Burn, near Hamilton. In only one other locality besides Australia does the genus occur, viz., at Antwerp, Belgium, in Crag deposits of Lower Pliocene age. =Sirenia.--=