422 THE HORSE OF ANAU IN ITS VARIOUS RELATIONS. 
Major’s index of the position of the facets the horse of Anau ranks very close to 
Equus stenonis and the horse of Solutré. In the following table I give again the 
mean values of this dimension for the different horses: 
ATIOU Bias rae cn te ie eterno terete 26.0 Stenonis, after Major....... 325 
Przewalski-4 meee acters 27:0 Bolted) Joy oie aes baie ees Seal 
Asinus, after Major och <0 nate) CASOMMIONG a tn. ees Relkiery 34.0 
Siberian horse, Tscherski.... 32.0 
In the neck of the astragalus the horses of Anau and of the Bohemian localities 
resemble throughout Equus stenonis and the recent horse. Kowalewski says that 
the cuboidal facet of the astragalus (which in the tridactyl ancestors of the horse 
was useful in transferring the weight of the body to the metatarsus externus) is 
very small in Hipparion and the horses and stands too steep to support the cuboi- 
deum. Moreover, Major has shown that it is still less steep in the horses than in 
Hipparion, but he admits that in Equus stenonis it is steeper in some specimens 
than in others. Among the Anau specimens small differences of this kind can be 
observed, showing that this characteristic is in a preeminent degree dependent on 
the individual use of the limbs. 
Naviculare tarsi—From Anau we have two specimens which were not con- 
sidered in the earlier chapter. For comparison, I have only those of Equus prze- 
walski and of a recent domestic horse. In the Anau horse, the indentation in 
the posterior edge of the naviculare (first mentioned by Kowalewski and of which 
he finds the first trace in Paleotherium medium) is uncommonly pronounced and 
deep, giving the tarsus great strength. In comparing this part of the naviculare 
with that in Equus przewalski we see that this indentation is here more round and 
hollowed out and not provided with so sharp-edged a notch as in the Anau horse. 
I find in the horses of Solutré and Kesslerloch the same condition as in Equus 
przewalsku., 
We know that the posterior edge of the astragalus joint is occupied by two 
projections which border this indentation. In Equus caballus the outer one usually 
projects strongly and is, as already stated by Riitimeyer (p. 11), much more 
strongly developed than in Hipparion. In the Anau horse the outer one projects 
the more; but in contrast with Equus przewalsku and the horse of Solutré, both of 
the Anau specimens show it connected in an almost straight line with the inner 
projection, and not separated by a deep notch as in those horses. Thus Equus 
pumpellw is, in this respect, very similar to Equus stenonis, in which the outer 
projections are described by Major as equal. 
The articulating surfaces for the cuneiforme I and II, which in Equus cabal- 
lus recens are much enlarged transversely, while in Hipparion and Equus stenonis 
the fore-and-aft diameter predominates, show in Equus pumpellii and przewalskii 
the same relation as in Equus stenonis. 
The articulating surfaces for the cuboideum: As Major observes, the center 
of gravity in the tarsus has been steadily moved forward from geological to recent 
time, hence the posterior articulating surfaces diminish in size and the anterior 
surfaces increase. ‘The posterior one of the two existing articulating surfaces is, 
especially in Hipparion, much extended from above down and stands here almost 
