442 



EXTINCT MAMMALIA OF NORTH AMERICA. 



defining tlie inner surface is sub-acute. Below the upper margin internally there 

 exists a row of small gingival foramina, directed forward. Rather more than half 

 an inch from the same margin there exists a row of large vasculo-neural foramina 

 directed obliquely forward. The canal within the bone throughout its length is 

 divided by a partition. The measurements of the specimen are as follow : 



Depth posteriorly, 34 lines ; anteriorly 34 lines. 

 Thickness posteriorly, 24 lines ; anteriorly, 22 lines. 



The caudal vertebra, from the anterior part of the series, is slightly longer than 

 the breadth, and its articular extremities are nearly circular and convex. The poste- 

 rior abutments of the chevrons extend nearly half the length of the body. The 

 transverse processes projected from near the middle of the latter about an inch and 

 three-fourths back of the edge of the anterior articulation. The spinal canal is nar- 

 row, not more than seven lines in width. The measurements of the specimen are as 

 follow : 



Length of body iuferiorly, 



Length of body laterally, 



Breadth of anterior articular extremity, 



Depth 



Breadth of posterior " " 



Depth 



Breadth of neural arch, 



Breadth of transverse processes, 



Escbriclitius cephalus. 



Cope: Proc. Ac.Nat. Sc. 1867, 131, 144, 148; 1868, 184, 193 ; 1869, 10, 11. 



Remains comprising a considerable portion of the skeleton, from the miocene for- 

 mation of Charles Co., Md. 



Hscliriclitms leptocentrus. 



Cope : rroo. Ac. Nat. Sc. 18G7, 144, 147 ; 1868, 193 ; 1869, 10, 11. 



Founded on an isolated cervical vertebra, devoid of epiphyses, from the miocene 

 formation of Virginia. 



iEscliriclitms expansus. 



Megajjtera c.qxima, Cope : Proc. Ac. Nat. Sc. 1868, 193. 



Exi-lirirhtius expansus, Cope: Proc. Acad. Nat. Sc. 1869, 11. 

 Founded on vertebroe from the miocene of Westmoreland Co., Virginia, and Charles 

 Co., Maryland. 



iEscliriclitius pusillus. 



Cope: Proc. Ac. Nat. Sc. 1868, 191, 193; 1859, 11. 



Ihihviiojitcm piiaUki, Cope: Proc. Ac. Nat. Sc. 1868, 159. 



f rhli,h;,u,i>trnis tj/raiiniix, Cope: Proc. Ac. Nat. Sc. 1868, 190; 1869, 7. 



Remains from the miocene of Maryland, and from the vicinity of Charleston, S. C. 



