16 M. Poliakof on a supposed new Species 
.Interorbital constriction .... 0°32 0:37 
Nasalibonespeemmnete a. aa. 0:45 0-40 
Anterior palatine foramina .. 0°23 0:20 
Upper molar series ........ 0:25 0:22 
Lower jaw, from condyles to 
Lip ROlMMCISOTS ie yell 0:80 0-78 
This species may be readily distinguished from A. decu- 
mana, annulata, and spiculum by the comparative shortness 
of its hind feet, from A. acontium and its allies by the cra- 
nial characters already mentioned, and from A. saltatrix*, a 
species which I only know from the original description, 
wherein no measurements are given, by the fact that in that 
species the usual white tip to the tail is absent, the tail ending 
in a wholly black tuft. 
III.— Supposed new Species of Horse from Central Asia. 
By M. PoutaKor. © 
[WE are indebted to Mr. EK. Delmar Morgan, already well 
known for his having rendered the travels in Mongolia of the 
celebrated Russian explorer, Colonel Prejevalsky, accessible 
to English readers, for the following translation of the de- 
scription and account by the Russian naturalist Poliakof, in 
the ‘ Izvestia,’ or ‘ Proceedings of the Imperial Russian Geo- 
graphical Society’ for January last (1881, pp. 1-20, pls. i. 
& il.), of a new species of horse presented by Prejevalsky to 
the Museum of the Imperial Academy of Sciences of St. 
Petersburg. | 
Prejevalsky’s Horse (Equus Przewalsku, n. sp.). 
For a very long time zoologists included among the repre- 
sentatives of the solid-hoofed family of the Ungulate order of 
Mammals only one genus, the Hqgwus of the present day. In 
1824, the English zoologist Gray formed a subdivision of the 
whole group, under the new generic designation Asinus. He 
characterized the genus Hquus as follows :—“ Tail wholly 
covered with hair, no dorsal stripe, warts on fore and hind 
legs ;” or “ Cauda undique setosa, linea dorsali nulla, verrucis 
brachiorum pedumque distinctis.” ‘The genus Asinus he dis- 
tinguished in the following way :—“ Tail furnished with hair 
only at extremity ; dorsal stripe present; warts on fore, but 
not on hind legs ;” or “ Cauda apice setosa, linea dorsali di- 
stincta ornatus, verrucis brachiorum distinctis, pedum nullis.” 
* Dipus saltator, Eversm. Bull. Soc. Nat. Mosc, xxi. p. 188, pl. i. 
(1848). 
