no. 2086. 



SOME MAMMALS OF THE PLEISTOCENE— HAY. 



537 



been found in two places along the Brazos River. In Nueces County, 

 probably in the same formation, Cope reported Equus associated 

 with a camel; and from the same region he described a Glyptodon. 

 From Bee County there have been obtained remains of Elephas im- 

 perator and Bison latifrons, probably too Bison regius. From about 

 San Diego have been described four species of extinct horses. 



A study of the remains seems to show that this horse is more closely 

 related to Equus tau Owen, than to any other yet described. Indeed 

 it is possible that it belongs to that species, but there are certain 

 features which appear to mark the animal as being more primitive 

 than Owen's species, and it seems, therefore, better for the present 

 to give it a distinct name. This shall be Equus francisci, in honor of 

 the discoverer. For figures of the skull see plates 35, 36, and 37. 



The following are the measurements of the skull. In the second 

 column are the corresponding measurements of a specimen of Equus 

 hemionus, which was collected by Dr. W. L. Abbott, on the Hanle 

 River, in Kashmir : 



Measurements of skulls in millimeters. 



E.frarir 



E. hemi- 



CISCl. 



onus. 



438 



470 



414 



445 



210 



222 



133 



153 



460± 



498 



110 



108 



328 



356 



270 



291 



310 



341 



316 



340 



100 



105 



167 



198 



99 



116 



100 



112 



50 



61 



68 



69 



130 ± 



137 



175± 



203 



152± 



166 



57 



74 



40± 



45 



39 



46 



60 



60 



352 



375 



380 



405 



54 



72 



70 



78 



195 



215 



72 



76 



From middle of incisive border to rear of occipital condyles 



From middle of incisive border to front of foramen magnum 



From middle of incisive border to rear of hard palate 



From middle of incisive border to naso-premaxillary notch 



From middle of incisive border to middle of occipital crest 



From middle of incisive border to front of pm a 



From middle of incisive border to rear of orbit, direct 



From middle of incisive border to front of orbit 



From middle of incisive border to notch at rear of vomer 



From middle of incisive border to middle of line joining rear of orbits (facial 



length) 



Width across mastoid region 



Width at glenoid fossae 



Width from outside to outside of last molars 



Width from outside to outside of last premolars 



Width from outside to outside of canines, at base 



Width from outside to outside of outer incisors, at base 



Width of skull at the front of the orbits 



Width of the skull at the rear of the orbits 



Width of skull on maxillary ridge at maxillo-malar suture 



Width of palate at last molars 



W idth of palate at pm a 



Wi dth of palate at diastema, least 



Length of orbit 



From front of symphysis of lower jaw to rear of ascending ramus 



From front of symphysis to rear of condyle 



Length of symphysis 



Height of jaw at front of m t- 



Elevation of condyle above lower border of jaw 



From rear of third incisor to front of pm , (diastema) 



In the above measurements of E. francisci certain dimensions 

 can not be determined with absolute accuracy, as is indicated in the 

 table. However, all of these, except perhaps the fifth, are so close 

 to the true values that the deviations may be neglected. The occip- 

 ital crest is broken away so badly that its border can not be de- 

 termined exactly. Although a considerable section is missing from 

 the skull in the region of the premolars, the connection of the snout 



