86 FLORIDA GEOLOGICAL SURVEY-EIGHTH ANNUAL REPORT. 
the upper Deep River beds of Montana.* (Miocene.) The Flor¬ 
ida horse, however, probably represents a somewhat more advanced 
species than P. crenidcns. First of all, the tooth, although smaller, 
is higher crowned; the crochet is more strongly developed; the pro- 
toloph likewise is connected with the outer wall and in the position 
of the protocone and hypocone, there is, however, a very close re¬ 
semblance particularly to the first molar of P. crenidcns. P. cren- 
idens was perhaps a slightly larger animal as the proximal phalanx 
referred to this species by Scott is somewhat larger than the prox¬ 
imal phalanx associated with the Florida species. From Parahip- 
pus tyleri Loomis this species is very distinct, the shape and posi¬ 
tion of the protocone and hypocone being very different in that 
species.f 
The species may be compared also with Archaeohippus ( An - 
chitherium) ultimum (Cope) Gidley. It differs from that species, 
however, and is also excluded apparently from that genus by the 
presence of the well developed crochet, as well as by the fact that 
the hypostvle is much more strongly developed than is that of A. 
ultim/ns. The lower molar, specimen No. 5083, it may be noted, is 
very similar to the lower molars of Archaeohippus ( Anchithcriuni ) 
agreste (Leid.v). The pronounced shelf on the inner side of the 
cingulum which is seen in the teeth of the two known species of 
Archaeohippus is not found on the teeth of this species. 
With the milk molars of Merychippus insignis one may recog¬ 
nize very suggestive resemblances. Thus the protocone and meta¬ 
cone have much the same form with a tendency to enlongation an- 
teroposteriorly. The hypostvle is similar except that in M. insignis 
it is entirely united with the metaloph while the union in the Flor¬ 
ida species is not complete. The milk molars of M. insignis thus 
present a stage in development beyond that of the permanent molars 
of this species. 
The teeth from the lower jaw are much worn and in their pres¬ 
ent condition there is but a faint suggestion of separation of the 
metaconid and the metastylid. The entostylid appears to have been 
about equally d.eveolped as in species of Archaeohippus. A cingu- 
* The Mammalia of the Deep River Beds, Amer. Philo. Sco, Trans., Vol. 
xviii, pp. 88-92, 1895. 
t Am. Jour. Sci., 4th Ser., xxvii, pp. 163-165, Aug., 1908. 
