1895.] 4b7 [Cope. 



the symphysis, thus again resembling the E. caballus. The mental fora- 

 men is behind the symphysis as in M. caballus, but the crowns of tiie 

 incisors have a transverse width proportionately equal to that of the inci- 

 sors of E. inter medias. This jaw belongs probably to a mare, as there is 

 no canine. » 



Both superior and inferior molars have the dentine marked with deli- 

 cate longitudinal ridges. This can of course only be seen where the 

 cementum has been lost. 



In the inferior molars the relations of the metaconid to the metastylid 

 are as follows. In two inferior molars (separate) they meet at a sharp 

 angle ; in five teeth they meet at a sharp angle, but gape widely apart ; 

 in three teeth the groove between them is rather shallow, as in the E. 

 occidentalis, but not so wide as in the E. eurysiylus and E. minimus. 



Measurements. mm. 



Diameters of crown of superior molar \ anteroposterior. 29 



(. transverse 24 



anteroposterior 25 



transverse 26 



anteroposterior 29 



transverse 17 



Length from inferior p. m. ii to edge of inferior incisors 128 



Width symphysis at base of I iii 58 



Diameters of do., No. 2 



Diameters of inferior p. m. ii 



In this form we have then one which, as remarked by Leidy, approaches 

 nearer to the E. caballus than any other. That it is a distinct species 

 from the common horse I strongly suspect, from its peculiar incisors, and 

 thinner enamel plates of the molars ; but it will be very desirable to 

 examine other parts of the skeleton and especially of the skull in order to 

 establish its true status. 



It remains to be understood to what species Leidy gave the name of 

 Equus fraternus. In the paragraph where Leidy first named it no locality 

 from which typical specimens were obtained is mentioned, and the 

 description will apply equally well to the E. intermedins. In Tuomey 

 and Holmes' Fossils of 8. Carolina, Leidy first definitely locates the 

 species as based on specimens found near Charleston, S. C. He figures 

 a number of molar teeth, some of which probably belong to the E. inter- 

 medius. The superior molar, which is first described, is figured on PI. xv. 

 Fig. 6 of that work. Unfortunately, the protocone of that tooth is largely 

 broken oflF, but enough remains to show that it had the very small antero- 

 posterior diameter characteristic of the Floridan teeth, and in other 

 respects it agrees with them, except that it is larger than usual. This is, 

 however, not sufficiently marked to be important. I therefore regard it 

 as the type of the species as described by Leidy, 



