310 
Proceedings of the Royal Society of Edinburgh. [Sess. 
In addition to assuming that the small horse which lived in the south 
of England along with the mammoth (the equine named by Owen Asinus 
fossilis) had slender limbs and the grinding surface of the pillars of the 
fourth premolar and first molar shorter than in the last two molars, it may 
be said that the fine-boned contemporary of Equus fossilis was probably 
as destitute of stripes as the wild horse now living in Mongolia, but had a 
mane long enough to arch to one side of the neck. 
About the origin of the small Oreston horse nothing is known. 
Perhaps it was a descendant of Equus sivalensis (the 15 hands horse with 
the face strongly deflected on the cranium which suddenly appeared in 
Table showing Differences between “ Steppe,” “ Plateau,” 
and “Forest” Types. 
Skull. 
Length of vertex ..... 
Basilar length 
Length of face* ..... 
Frontal width 
Frontal index 
Premaxilla length .... 
Premaxilla-frontal index 
Occipital foramen to vomer . 
„ „ to palatine 
Palatal -frontal index . 
Deflection of face on cranium 
Teeth. 
Length of six cheek teeth 
„ of premolar 1 . 
Size „ 4 . 
Length of pillar, premolar 4 
Size of molar 1 .... 
Length of pillar, molar 1 
Size of molar 2 
Length of pillar, molar 2 
Width across incisors .... 
Gannon Bones. 
Metacarpal III. . . . f wicftb 
Metatarsal III. . . . f H 
Vertebrce. 
Lumbar vertebrae 
Caudal „ 
“ Steppe,” 
E. przewalskii. 
“ Plateau,” 
E. agilis. 
“ Forest,” 
E. robustus. 
518 mm. 
494 mm. 
506 mm. 
460 „ 
442 „ 
451 „ 
371 „ 
338 „ 
336 „ 
187 „ 
185 „ 
206 „ 
50-4 
54-8 
6P3 
180 mm. 
182 mm. 
171 mm. 
96*2 
98 
83 
119 mm. 
112 mm. 
112 mm. 
205 „ 
212 „ 
215 „ 
109 
114 
104 
16° 5' 
o 
0 
00 
2° 4' 
180 mm. 
162 mm. 
169 mm. 
3 „ 
7 „ 
absent 
29 x 30 mm. 
27 X 26 mm. 
28 x 27 mm. 
14 „ 
9 „ 
14 „ 
26 x 29 „ 
24x25 „ 
25 x 26 „ 
14 „ 
9 „ 
14 „ 
26x27 ., 
24x25 „ 
25 x 25 „ 
13*5 „ 
13 „ 
15 „ 
76 „ 
62 „ 
72 „ 
?°? = 6-6 
214 -7-5 
«-8 
31 
28*5 
35 
^ = 8-0 
*57-9-2 
237 = 7-l 
31 
28 
33 
5 
5 
6 
18 
16 
18 
Distance from line connecting supra-orbital foramina to alveolar point. 
