VERTEBRATE FAUNA OP THE BLANCO BEDS. 67 



EQUUS CUMMINSII, Cope. 



Sp. nov. Plates XX, Figure 7; XXIII, Figure 1. 



Three superior molars represent this species. They were found at 

 different localities in the neighborhood from which we obtained the 

 teeth of the E. simplicidens. They represent an animal of considerably 

 smaller size than the latter, measuring with the E. tau and E. semi- 

 pUcatus. Their enamel borders are entirely simple, as in E. simplicidens 

 and are hence different from those of the E. semiplicatus. It differs from 

 both the E. simplicidens and the E. tau in the prominent convexity 

 of the internal wall of the paracone and metacone, from which it results 

 that the external border of each lake is deeply concave, and the horns 

 appear to be strongly produced. The pi'otocone has a very short an- 

 teroposterior diameter, in which it resembles the E. simplicidens^ E. 

 crenidens and E. stenonis, and differs radically from the E. tau and 

 the other species of the Equus beds. It is not bilobate or grooved on 

 the internal face. There is an angle of the posterior border of the 

 anterior lake which represents the loop, but no other complications of 

 the lake borders, except that in one specimen there is a notch in the 

 anterior border of the posterior lake and a trace of a notch on the remote 

 borders of both lakes. 



The crowns are well worn in two of the molars, but that the characters 

 of the enamel plates are not due to wear is shown by the third specimen, 

 where the crown is 47 mm. long. The measurements of the best pre- 

 served crown are: length, 33 mm.; transverse diameter, 24 mm.; antero- 

 posterior, 24 mm. 



The subcylindric character of the paracone and metacone approach what 

 exists in Hippidium and some species of the three-toed horses. The 

 species is named in honor of Mr. W. F. Cummins, who has done so 

 much for the geology and paleontology of Texas. 



EQUUS MINUTUS, CopC. 



Sp. nov. Plate XX, Figure 8. 



This species is represented by an inferior molar from near the middle 

 of the series from Mount Blanco. Some other fragments of teeth of the 

 species were obtained, but I can not at this writing place my hands upon 

 them. 



The inferior molar is narrowly hypsodont, and has apparently had but 

 a thin cementum investment. This appears probable, from the fact that 

 it is as thin where protected from weathering as where exposed to it, i. e. , 

 in the groove between the external columns. The inner side of the 

 crown shows marked peculiarities. The metaconid and metastylid are 

 appressed to the hypoconid and protoconid, and are spread widely apart 



