USTO- IS. 

 THIRD NOTICE OF EXTINCT VERTEBRATA FROM THE TER- 

 TIARY OF THE PLAINS. 



By Edward D. Cope. 



Insectivora. 

 Domnina gradata. Gen. et sp. nov. 

 Represented by a portion of the right mandibular ramus with three 

 entirely preserved molars. These teeth increase in size regularly from 

 behind forwards, so that the anterior is relatively large ; there are no 

 indications of alveoli anterior to this one, but a considerable internal 

 canal rises in front of it, and the mental foramen issues below it. The 

 crowns of the molars are composed of two rows of alternating tubercles 

 with an odd one in front. The inner tubercles are much the more 

 elevated and form the apices of Vs, of which the inner commence the 

 limbs. 



Char, specif. Three rows of acute tubercles on the inner, two on the 

 outer side of each dental crown, the last pair of the last crown fused into 

 a heel ; the middle inner and anterior outer forming together a notched 

 yoke. A low cingulum on outer, none on inner basis of tooth crown ; 

 enamel smooth. 



Measurements. 



M. 



Length of basis of three molars 0055 



" " first " 0023 



" " last " 0015 



Depth of ramus at first molar 0026 



Width of first molar 0015 



Herpetotheritjm: euzax. Gen. et sp. nov. 



Established on a left mandibular ramus incomplete at both extremities, 

 but exhibiting the crowns and alveoli of five molar teeth. These dimin- 

 ish in size anteriorly, and there is no anteriorly exposed canal or alveolus, 

 and there is no mental foramen visible. The crowns are composed of 

 two rows of tubercles, but the inner are low and sometimes obsolete, and 

 there is an anterior lobe. The inner lobes are much the higher. 



Char, specif. Enamel smooth, no cingulum on either side. Molars 

 truncate behind. Outer anterior lobe acute, considerably the higher. 



Measurements. 



M. 



Length of bases of four molars 0070 



" " second " .0020 



Width " « " 0012 



Depth of ramus at " '• 0030 



This species and the last were about the size of our mole, and no 

 doubt possessed similar insectivorous habits. 



