18 M. Poliakof on a supposed new Species 
Genus 11. ASINUS. 
Verrucis brachiorum distinctis, pedum nullis ; artubus gracilioribus ; 
ungulis contractis, subcylindraceis ; cauda apice setosa. 
Without recapitulating here the various species of ass com- 
prised in the genus, let me say that all other distinguishing 
marks mentioned by Gray are only of relative importance. 
Thus, he lays stress on the dorsal stripe, saying of the horse 
‘¢ jinea dorsali nulla,” and of the ass “ linea dorsali distincta ;” 
whereas Isidore Geoffroy de St.-Hilaire remarked that this was 
of no real importance, because many horses have astreak along 
the back, and, on the other hand, not a few asses are without 
it (vide ‘‘ Sur le genre Cheval et spécialement sur |’ Hémione,” 
extrait des Nouvelles Annales du Musée d’ Hist. Natur. vol. iv. 
p- 1). He, too, observed, that the distinction “ cauda apice 
setosa”’ properly only applies to the djiggetai,—the ass, and 
particularly the zebra, besides other striped species of the 
solid-hoofed animals, having tails furnished with hair so as to 
form a regular gradation from the tail of the horse to that of 
the djiggetai. The tail of my horse must be regarded as inter- 
mediate between the horse and the ass; it is, however, so well 
furnished with hair at the extremity and is so bushy, thick, 
and bristly at the root, as to differ from most asses; and I 
am inclined to attach weight to the characteristic “ cauda 
apice setosa” as distinguishing the asinine genus from the 
equine. Upon the whole, therefore, I dissent from Isidore 
Geoffroy de St.-Hilaire, in so far as he rejects Gray’s divi- 
sion of the solid-hoofed mammals into two genera. My horse 
has the mane of an ass, and resembles it further in having no 
forelock. Besides the above-mentioned distinguishing marks, 
asses differ from horses in having more slender legs and 
narrower hoofs. And as regards warts, these occur on the 
fore legs of all asses, and have the appearance of smooth 
hairless patches; whilst with horses they take the shape of 
horny excrescences, particularly on the hocks. ‘Taking also 
into consideration the skull as another distinguishing feature 
between the ass and the horse, although it may be only in the 
size of its several parts, Gray’s division of the solid-hoofed 
animals must, I think, be upheld. 
The materials I have availed myself of in comparing this 
new species of horse with others are :—the stuffed specimens, in 
the Zoological Museum of the Academy of Sciences, of Bur- 
chell’s horse and zebra; a domestic ass; two kiangs (Asinus 
kiang) brought by Prejevalsky from Northern Tibet; four 
stufted kulans (Asdnus onager, Pall.), two from General Pol- 
toratzky’s collection in Kastern Dzungaria, and two from the 
