PHYSETERms:. 57 



44044. An imperfect tooth ; from Woodbridge. Purchased, 1873. 



27518. The greater part of a rolled tooth ; from Felixstowe. 



Purchased, 1852. 



27435. A rolled tooth ; from Felixstowe. Purchased, 1851 . 



Genus PHYSETODON, M'Coy '. 



The teeth of this genus are described as being very similar to 

 those of Physeter, but distinguished by the small size of the aperture 

 of the pulp-cavity at the base of the root ; in this respect they 

 resemble the teeth of Eucet us, and further observations are required 

 to prove their generic distinction. 



Fhysetodon baileyi, M'Coy 2 . 



This is the type and only species. 

 Ifab. Australia. 



43996. The imperfect upper half of a tooth ; from the Lower Plio- 

 cene of Mordialloc, Hobson's Bay, Victoria. This specimen 

 agrees very closely with the type teeth figured by M'Coy, 

 op. cit. pi. Iv. Purchased, 1872. 



Genus SC ALDICETUS, Du Bus 3 . 



The teeth are somewhat smaller than those of Physeter macro- 

 cephalus, and are distinguished by a coat of grooved enamel on the 

 summit of the crown. The section of the tooth is subcircular ; the 

 cement is abundant and much thicker in the middle than at the 

 two extremities, thus causing the tooth to be fusiform ; the dentine 

 core is subcylindrical throughout the greater part of the tooth ; and 

 the central axis of dentine very slender, darker in colour than the 

 overlying layer, and without a nodular structure. In young 

 specimens the pulp-cavity is open and conical in shape. 



1 Palaeontology of Victoria (Geol. Survey of Victoria), dec. vi. p. 19 (1879). 



2 Loc. cit. 



3 Bull. Ac. E. Belg. ser. 2, vol. xiiv. p. 568 (1867). 



