in. EXTINCT SPECIES OF AMERICAN OX. 17 



Length ......... 9 inches, 7 lines. 



Breadth at the proximal articulation . . . 3 " 4 " 



« distal « . . . . 3 " 5 " 



Circumference at middle . . . . . . 6 " 3 " 



Among the collection of Jefferson from Big-bone Lick, there is a specimen of a 

 right metacarpal in perfect condition, which may also probably belong to Buoth&- 

 rium cavifrons, although it is a little larger than that last described. It is not im- 

 probable that it might belong to Bison latifrons. 



Its measurements are as follow : — 



Length ........ 



Breadth at proximal end . . . 



" distal " .... 



Circumference at middle 



A metatarsal bono and a first phalanx, in the collection of Jefferson, probably 

 also belong to this species. The former is of the left foot, and is a little shorter 

 and considerably less robust than the corresponding bone from Georgia, attributed 

 to the Bison latifrons. 



Its measurements are as follow : — 



Length . . , . . . . . .10 inches. 



Breadth of proximal articulation . . . . 2 " 3 lines. 



distal " .... 2 " 7 " 



Circumference at middle . . . . . 4 " 9 " 



The phalanx measures three and a quarter inches in length. 



BOOTIIERIUM BOMBIFEOXS, Leidy. 



, Wistar: Trans. Amer. PLil. Soc. n. s. \o\. I. p. 359. 



Bos bomhifrons, Harlax : Fauna Americana, p. 271 ; Med. and Phys. Ive.«!. p. 275 ; Edinb. New Phil. .Journ. 

 XVII. 359; Cooper, Smith, and De Kay: Amer. Journ. Sci. XX. 370; CoorER ; Am. IM<iiith. Journ. uf 

 Geol. Vol. I. p. 173; De Kav: An. Lye. Nat. Hist. II. 286; New York Fauna, Zool. I't. 1, p. 110; 

 Meter : N. A. A. Nat. Cur. XVII. p. 143. 



Bootherium bomhifrons, Leidy : Proc. Acad. Nat. Sci. Vol. VI. p. 71. 



The only characteristic specimen which I have seen of the Bootlicriinn homh'b- 

 frons, is that first described and figured by Dr. Wistar from the collection of Jelfer- 

 son. It consists of the cranium proper, with both horn-cores attached, and presents 

 the ordinary condition of preservation of all the preceding bones described from 

 the morasses of Big-bone Lick (Plate IV., Fig. 2 ; Plate V) . 



The upper outline of the head of Bootherium bomhifrons, when viewed laterally 

 (Plate v.. Fig. 1), rescmljles in its posterior rise from the inion and its abrupt 

 declination forward that of the Sheep. The os frontis, instead of forming an ex- 

 ostosis-like process, as in Bootlierlum cavifrons, rises gradually from its com- 

 mencement anteriorlv, and forms a sort of hump, from the sides of which, like 



