EXTINCT MAMMALIA OF NORTH AMERICA. 435 



Tretosphys nrsens. 



Cope : Proc. Ac. Nat. Sc. 1869, 7, 8. 



Founded on a lumbal' vertebra from. Shilob, Cumberland Co., N. J., and a caudal 

 from near the mouth of the Patuxent, Maryland. 



Tretosphys Ruschenbergeri. 



De/jihinapterus Ruschenhergeri, Cope : Proc. Ac. Nat. Sc. 1868, 189. 

 Tretosphys Ruschenhergeri, Cope : Proc. Ac. Nat. Sc. 1869, 7, 9. 



Founded on a caudal and a lumbar vertebra, from the miocene of Charles Co., Md. 



ZARHACHIS. 



Zarhachis flagellator. 



Cope: Proc. Acad. Nat. Sc. 1868, 189, in part; 1869, 9. 



Founded on a caudal vertebra from the miocene of Charles Co., Md. 



Zarhachis Tysoni. 



Zarhachis JlagcUator, in part of Cope: Proc. Ac. Nat. Sc. 1868, 189. 

 Zarhachis Tysonii, Cope : Proc. Ac. Nat. Sc. 1869, 9. 



Founded on a lumbar vertebra from the miocene of the Patuxent, Maryland. 



Zarhachis velox. 



Zarhachis flagellator, in part of Cope: Proc. Ac. Nat. Sc. 1868, 189. 

 Zarhachis velox. Cope : Proc. Ac. Nat. Sc. 1869, 10. 



Founded on a lumbar vertebra from the miocene of Shiloh, Cumberland Co., N. J. 



LOPHOCETUS. 



Iiophocetns calvertensis. 



Deljjhinus Calvertensis, Harlan : Pr. Nat. Inst. Washington, 1842, 195, accom. with 3 pis. Dekay: 



Nat. Hist. New York, Zool. Pt. I, 1842, 1.36. Markoe: L'lastitut, 1842, X, 384; Jahrb. f. 



Mineralogie, 1843, 238. 

 Pontoporia calvertensis, Cope : Proc. Ac. Nat. Sc. 1866, 297. 

 Lophocetus calvertensis. Cope : Proc. Ac. Nat. Sc. 1867, 144, 146. 



Indicated by a skull from the miocene of Calvert cliffs, Maryland. 



RHABDOSTEUS. 

 Rhabdostens latiradix. 



Cope : Proc. Ac. Nat. Sc. 1867, 132, 144, 145. 



Founded on fragments of jaws and teeth from the miocene of Charles Co., Md. 



IXACANTHUS. 

 Ixacanthns coelospondylns. 



Cope : Proc. Ac. Nat. Sc. 1868, 159, 187. 



Founded on vertebra from the miocene of Charles Co., Md. 



