226 



EVOLUTION OF MAMMALIAN MOLAR TEETH 



FIG. '20f. Internal view of the right upper and lower cheek teeth of the Zalambdodont 

 Insectivore Cfntitm (No. 1), the Marsupial Diddphys (No. "1), the Dilambdodont Insectivore 

 Erinaceus (No. 3) and the Titanotheroid Ungulate Telmatherium (Xo. 4). The main internal cup 



small talonid (Olikc a normal protocone, but is somewhat external to it, and occupies the position 



of an inwardly grown paracone. 



(See Addendum, p. 225). ED.] 

 p = protocone. 

 h =hypocone. 

 m = metaconid. 



t = talonid. 



