TRANSACTIONS OF WAGNER 

 SO 



HIPPOTHERIUM . 



posterior crescent by a slight notch only. The free borders of the lakes have 

 each a single infolding of enamel, while their apposed borders are folded into 

 several narrow but not greatly complicated sinuses. 



Fore and aft diameter of tooth . . . ... .18 mm. 



Transverse diameter of tooth . . . . . . 17 " 



The astragalus, plate xviii. fig. 15, is characterized by the prominence of 

 the trochlear keels, but, except in size, does not differ otherwise from the 

 astragalus of the horse. 



Greatest height of astragahis on inner face .... 36 ram. 

 Width of astragakis across navicular face . . . . 28 " 



The proximal phalanx, plate xviii. fig. 16, ascribed to this species seems 

 from its length and slenderness to belong to a hind leg. Its posterior upper 

 face is deeply and widely excavated for the tendon. 



Greatest length of phalanx . . . ... -58 mm. 



Greatest proximal width . . ■. . . . . 24 " 



Greatest distal width 20 " 



F. A. L. 



Hippotheruim plicatile 



Five molars and a number of bones of the extremities, mostly incom- 

 plete, are assigned to this species. A right upper molar, plate xix. fig. 2, 

 probably the third, has the anterior internal pillar quite regularly elliptical in 

 section, and the posterior pillar well marked off by infoldings of enamel. 

 The adjacent borders of the lakes have numerous infoldings of enamel, giving 

 a very complicated pattern, while their free borders are slightly wavy with 

 the usual re-entrant fold, and the inner border of the anterior lake comprises 

 several large and numerous small folds. 



Fore and aft diameter of tooth ...... 20 mm. 



Transverse diameter of tooth . . . . . 23 " 



The radius, plate xix. figs. 3 and 4, resembles that of the horse, on a 

 smaller scale. The ulna is complete and, except for a distance of 45 mm. at 

 its proximal portion, united with the radius ; the distal articulation is marked 

 off from that of the radius by a shallow groove. 



