154 Eaton— Yertebrate Fossils from Ayusbamba, Peru. 



Dimensions of skulls in millimeters. 





J3 PI 



a to 

 pi t* 



'!§ 



a a 



o ce 



« 



to 



I* 



ci g 



Length, total 



From posterior margin of foramen magnum to anterior 



border of p 2 . . 



From posterior margin of foramen magnum to posterior 



border of m 3 - 



From posterior margin of foramen magnum to anterior 



border of orbit ... 



From occipital point to anterior border of orbit 



Maximum zygomatic breadth 



Zygomatic breadth across glenoid surfaces 



Occipital condyles, maximum height 



Occipital condyles, maximum breadth 



Breadth across outer margins of condyles 



Breadth of os occipitale 



Breadth of os occipitale + os petrosum 



Height of occipital region 



Maximum height of foramen magnum ._ 



Maximum breadth of foramen magnum 



588 



430 



244 



241 

 268 

 220 

 216 



46 



33 

 102-5 

 129+ 

 141 

 126 



47 5 



45 



580 

 410 

 231 



230 



248-5 



213 



207 



40 



26 



90 

 115 

 134 

 108 



34 



45 



228* 



222 



248 



200 



191 



39 



25 



84 



110 



125 



110 



37 



32 



The fossil horses that have been found in the mountains of Peru 

 and Bolivia apparently belong to small short-legged species of 

 Parahipparioji, while Onohippidixim compressidens. an animal 

 with larger head and longer limbs, has been found only in 

 the pampas formation of the Province of Buenos Ayres, near 

 the Atlantic coast. 



* Taken to the alveolus. 



f Sefve gives 2l9 mm . According to the context this should read 129 mm . 



