I go I.] Gidley, The North American Species of Eqiius. Ill 



the type of this species; it is evident that Cope made a mistake 

 in this selection, for the tooth to which he referred was not de- 

 scribed at all by Leidy but simply mentioned and that not until 

 after the teeth represented by figures 19-22, PI. xvi, and figure 8, 

 PI. XV, had been described. The teeth represented by figures 19- 

 22, PI. xvi, are a composite lot of undistinguishable lower teeth 

 regarded by Leidy as belonging to E. complicatus and E. fraiernus. 

 Since he mentioned figures 19 and 21 as exhibiting " a greater 

 degree of plication in the enamel than is usual in any of the lower 

 molars of the horse, whether recent or extinct," he evidently re- 

 garded these two teeth as belonging to E. complicatus and prob- 

 ably regarded the other two as belonging to E. fraternus. But as 

 there seems to be really nothing in the teeth themselves by which 

 they can be separated or distinguished, the choice of the type of 

 E. fraternus seems necessarily to fall on the next described tooth 

 which is represented by figure 8, PI. xv, and described on page 

 102 of the above work. 



This tooth', taken by the writer as the type of E. fraternus (see 

 Figure 8, A^ No. 9200, Coll. Am. Museum Nat. Hist.), seems to 

 represent in general the teeth to which Leidy intended to apply 

 this name, and seems to represent also this species, as understood 

 by Cope, more nearly than the tooth selected by him as the type. 

 Cope evidently was led to error in the description of his selection 

 of the type by the poor representation of this tooth as originally 

 figured by Leidy, for Figure 8,^, a careful drawing'taken from the 

 tooth itself, shows that the protocone has not the " characteristi- 

 cally small antero-posterior diameter " which he attributed to the 

 Florida specimens, but is rather large. As there seems to be 

 nothing then to separate this tooth from E. complicatus^ it should 

 properly be referred to that species. 



E. fraternus (thus clearly separated from the type used for it 

 by Cope and based upon the first characteristic specimen men- 

 tioned by Leidy) then represents a rather small species of horse 

 about intermediate in size between E. complicatus and E. tan as 

 described and figured by Owen, with the enamel foldings inclined 

 to be quite complicated in pattern, as is indicated by two other 

 teeth, in the American Museum collection, probably belonging to 

 this species (Nos. 9217 and 9203, Coll. Am. Museum, represented 

 by figure 8, Cand £>). The side views of the crowns show that they 



