84 FLORIDA GEOLOGICAL SURVEY-EIGHTH ANNUAL REPORT. 
Generic Relation.-. This species is clearly to be referred to the 
Anchitheriinae as indicated by the brachyodont permanent molars 
having only a very light coating of cement. Of the five known 
American genera of Anchitheriine horses one, namely, Mcsohippus 
may be omitted, from consideration since the Florida species is much 
advanced beyond the stage represented by the species of that genus; 
nor can the species be referred to the European genus Anchitherium 
from which it is excluded by the pronounced fold in the anterior 
wall of the metaloph. From Hypohippus this species is excluded 
by the presence of a well developed crochet, as well as by the fact 
that the protoconule and metaconule are not so reduced as in that 
genus, the protocone occupying less than one half the traversed di¬ 
ameter of the crown of the tooth. From Archaeohippus as defined 
by Gidley* the species is seemingly excluded by the pronounced an¬ 
terior fold of the metaloph, and by the fact that the prefossette ow¬ 
ing to this fold is not continuous with the inner median valley of 
the tooth. It resembles Archaeohippus, however, in the fact that 
the constriction separating the protocone and protoconule is formed 
chiefly in the anterior wall of the protoloph. 
With Parahippus, the one remaining known American genus 
of Anchitheriine horses, the species agrees in having a well defined 
anterior fold in the metaloph. It is unlike many of the species of 
that genus in the fact that the inner conules, protocone and, hypo- 
cone, form no part of the inner boundary of the pre and post- 
fossette, from which they are excluded by a pronounced develop¬ 
ment of the crochet and hypostyle. In fact the hypostyle and crochet 
lack but little completing the connection with the metaloph and 
protoloph respectively which is clearly the tendency of development 
in the tooth. The connection of the hypostyle is at the inner mar¬ 
gin of the metaconule just at the constriction which separates it 
from the hypocone; the connection of the crochet likewise is with 
the inner margin of the protoconule at the constriction which sepa¬ 
rates it from the protocone. It requires only the union of the hy¬ 
postyle and crochet with the metaloph and protoloph to complete 
the inner crescent of the tooth, thus giving a transition to the fun¬ 
damental pattern of the protohippine tooth. 
Of the described species of Parahippus this species presents ap- 
* American Museum of Natural History, Bull., Vol. xxii, p. 385, 1906. 
