PTEROPCS ANETIANU3. 



283 



have the teeth much worn. Posterior basal ledge of p^ rery strong, 

 sharply separated postero-esternally by a well-marked notch from 

 base of outer main cusp ; postero-external corner raised into a small 

 rounded tubercle ; postero-internal margin of ledge continuous with 

 liinder margin of inner main cusp ; antero-internal basal portion of 

 p^ often more differentiated tlian usual, forming a small " heel,"- 



Fig. 14.- 



-Pteropiis atictianiis, (^ . Aneiteum. No. 7.1.1.255. I, with 

 left Pj, Pj(, Bii, and m^ enlarged (?, linear). 



with or without minute tubercle. Posterior ledge of p* well 

 developed, sharply separated postero-externally by a distinct notch 

 from base of outer main cusp ; the ledge is much more developed 

 on postero-internal than on postero-external corner of tooth, making 



u 



