262 T. 8. Hall: 



chaic than anything found in Squalodon, but occurs in the Fayum 

 Prozeufjlodoti} This character is regarded by Andrews as of 

 generic value. 



The diflferences which exist in the teeth are, I think, of suffi- 

 cient importance to enable us to separate three genera which 

 may be referred to the Squalodontidae and may be defined as 

 follows : — 



Kbkbnodon, Hector. 



Teeth with massive roots, three or four times as long as the 

 crown. Roots usually united for their whole length, and in 

 every case never widely separated. A third root in some teeth. 

 Lateral cusps on the crowns strong and freely projecting. Sur- 

 face of crowns, according to Hector, fluted. 



Only species Kekenodon onamata, Hector. 



Parasqualodon, gen. nov. 



Roots of molariform teeth slightly more than twice the 

 length of the crown. Roots united throughout their length and 

 in some teeth slightly hooked at the end. Lateral cusps on 

 the teeth rather small. Surface of crown covered with cord like 

 the tip of the tooth. Ridges roughened with small rounded pro- 

 minences. In the (?) premolar figured (PL XXXVI., Fig. 3) the 

 sharp edges of the teeth are slightly serrated, the serrations varying 

 in size from these prominences to distinct, though small, cusps. 

 Anterior teeth with the same cordlike ornament, but without 

 lateral cusps, and from the same horizon, are provisionally refer- 

 red to the same genus and species. 



Only species Parasqualodon wilkinsoni, M'Coy. 



Metasqualodon, n. g. 



Roots of molariform teeth slender and only a little longer 

 than the height of the crown, the two fangs connected by a thin 

 " isthmus " much as figured by Lydekker in Prosqualodon. but 

 the fangs more nearly approaching one another. The material 

 does not inform us as to whether the fangs were connected 



1 Andrews, p. 251. 



