Squalodon and Zeuglodon. "^59 



The specimen consists of merely parth^ hollow crown packed 

 with the characteristic large, well-rounded quartz grains of the 

 basal beds at Table Cape. A reference to the figure will show 

 the obliquity of the crown and the presence of two large 

 cusps on the front edge, and three on the hind one. This points 

 in the direction of the Squalodonts rather than of the Zeuglo- 

 donts. Tlie crown is higher and narrower than M'Coy's type, 

 and thus approaches the more anterior tooth figured from Spring 

 Creek. Though the root is absent I am of opinion that the 

 Table Cape specimen is conspecific with M'Coy's species, and 

 is more anterior than his type. 



The Victorian National Museum has a fine molar from the 

 Mount Gambler polyzoal limestone, which has been referred to 

 above. 



I have what appears to be a premolar from the Middle Spring 

 Creek beds, which I found several years ago. These are all the 

 records or material of which I can find trace. No other bones 

 belonging to these whales have been found unless some of those 

 recorded as " Cetotolites " may be so referred. 



Hector's Kekenodon in some ways stands apart from all the 

 others. The crowns of the teetii as compared with the roots 

 are much smaller. The surfaces of the crowns are stated by 

 Hector to be fluted and polished. Casts of some of the teeth are 

 in the National Museum here, but the flutings are not shown, 

 and cannot, I think, have been as pronounced as in *S'. wil- 

 kinsoni. 



We have then three species, which, as I shall attempt to show, 

 it w^ould seem advisable to refer to as many distinct genera. 



The separation of the Zeuglodontidae and the Squalodontidae 

 rests fundamentally on the formation of the skull, the Zeuglo- 

 donts being more generalised, or archaic, in that the anterior 

 nares are far forward, the nasals being large. Both 

 families are usually grouped with the Cetacea, the latter as a 

 distinct sub-order, Archaeoceti or Zeuglodontes. The Squalo- 

 donts with small nasal bones, and an anterior nasal opening on 

 the top of the head, are grouped with the Odontoceti under the 

 family Squalodontidae. 



The only suggested difference shown b)' the teetli in the two 

 families is, as has been pointed out by several observers, that 



3a 



