VERTEBRATE REMAINS, PORT KENNEDY BONE DEPOSIT. 255 



synopsis of characters of such North American species as I am familiar with, as 

 seen in the dentition. 



I. Small species with sharp-angled molars. 



A prominent longitudinal keel at middle of external side of crown ; 

 small ; E. eurystylus Cope. 



No external longitudinal ridge ; least ; E. minutus Cope. 



II. Larger species with rounded angles of crowns of molar teeth. 



A. Protocone 2.5 to 3 times in length of crown on true molars. 

 Size medium ; enamel less or more complex ; incisors -g-.-g- without inner 

 cup-walls ; E. fraternus Leidy. 



Size very large ; protocone grooved on internal face ; complexity 

 moderate ; E. crenidens Cope. 



Size small ; lake border simple ; E. cnmminsii Cope. 



A A. Protocone .5 to .66 long diameter of crown on true molars. 

 a Smaller species ; molars 25 X 25 ± mm. 



Enamel borders simple ; protocone very flat ; E. tau Owen. 



Enamel borders a little infolded ; last superior molar equal penul- 

 timate ; E. semiplicatus Cope, 

 aa Larger species ; molars 30 X 35 ± mm. 



Protocone of premolars narrow ; enamel of molars little complex ; last 

 superior molar larger than penultimate ; inferior incisors, entire ; 



E. occidentalis Leidy. 

 Protocone of premolars equal that of molars ; enamel moderately 

 plicate ; external inferior incisor without posterior cup-wall ; 



E. intermedins Cope. 



Protocone of premolars equal that of true molars ; enamel folds very 



complex ; E. complicates Leidy. 



Equus fraternus Leidy, Proc. Acad. Nat. Sci. Phil, 1858, p. 11 ; Postpliocene Fossils of South Carolina, 

 Tuomey and Holmes, 1859, p. 100, PI. XV, figs. 6, 8, 16, 17, 18 ; PI. XVI, figs. 23, 27-9. Cope, Proc. 

 Am. Phil. Soc, 1895, p. 465. 



This horse is represented by the following specimens : A decayed skull of a 

 young animal containing molars and incisors, a number of them in place and 

 unworn ; a series of twelve superior molars and three superior incisors, now sepa- 

 rate, but found together, and probably belonging to one animal ; a series of ten 

 superior molars and three incisors, all found at the same time, and separated by the 

 quarrymen, but apparently belonging to one skull, excepting one which is a dupli- 

 cate ; two upper molars and one upper incisor, found at the same time and distin- 

 guished from the others by their dark color ; parts of both mandibular rami of one 

 animal, containing twelve molars with the symphysis and all the inferior incisors in 

 place, also of dark color ; and part of another ramus containing four molars. These 

 specimens indicate seven individuals. There are also bones of the skeleton, but 

 these are not very numerous. 



The superior molar teeth all agree in the fact that the anteroposterior diameter 



