20 TRANSAC'I'IONS OF THE WAGNKR FREE 



phalanx and an astragalus, in the collection from the Smithsonian Institu- 

 tion, likewise accord with the same bones in the latter animal. 



3. An interesting fossil from Peace Creek is a pastern bone or first 

 phalanx, which I suspect to belong to the three-toed Horse, Hippotheriunt. 

 The specimen, represented in figure 2, plate III., indicates a small animal of 

 slender proportions. It is related in size with an a.stragalus and an upper 

 molar tooth, from Archer, Levy Co., Florida, on which were based the 

 HippotJicrinvi iiigeiiinnn, noticed in the Proceedings of the Academy of 

 Natural Sciences, p. 33, Philadelphia, 1885. The three specimens accord 

 in size with one another, as do three corresponding specimens from Archer, 

 Florida, on which was based another species under the name of Hippo- 

 thcrhiDi plicatilc. 



The pastern, from Peace Creek, regarded as belonging to Hippotherium 

 ingemntni, in comparison with that of H. plicatilc from Archer, and another 

 found in association with the former and not differing from the pastern of 

 the Domestic Horse, show the following comparative measurements : 



H. ingenuum. 



Length of the pastern, . . . 58 mm. 



Transverse diameter of proximal extremity, 23 " 



middle of shaft, . 15 " 



" " distal extremity, 19 " 



The astragalus of Hippotlierium ingenuiiDi from Archer, Levy Countj% 

 Florida, is represented of the natural size in figure 4, plate III. It differs 

 in no respect anatomically from the corresponding bone of the Domestic 

 Horse except size. Its comparative measurements with a specimen pertain- 

 ing to H. plicatilc from the same locality, and another of the Horse from 

 Peace Creek, are as follows : 



H. ingenuum. H. plicatile. Equus. 



Height of the tibial trochlea internally, 36 mm. 49 mm. 67 mm. 



Width of the tibial trochlea at middle, 28 " 40 " 60 " 



Fore and aft width of scaphoid articulation, 20 " 29 " 37 " 



Transverse width of calcanean articulation, 26 " 35 " 50 " 



The upper molar tooth originally described as characteristic of Hippo- 

 theriwn ingcmnim is represented in figure 3, plate III. In its extreme 

 length, at the outer fore part, it is 47 mm., and in size approximates a 

 similar tooth, from the phosphate beds of Ashley River, South Carolina, 

 described under the name of Hippotlierium vcnnstinii, in Holmes' Post- 

 pliocene Fossils of South Carolina, i860, p. 105, pi. XVI., fig. 33. In the 

 Ashley specimen the inner column of the tooth is lost, but otherwise the 



H. plicatile. 



Equus. 



50 mm. 



60 mm 



35 " 



50 " 



25 " 



33 " 



27 " 



42 " 



