1980 MACFADDEN & WALDROP: FLORIDA NANNIPPUS PHLEGON 31

related, or ancestral, to N. phlegon. Cope (1893) originally described
the species Protohippus lenticularis based on two upper molars of late
Hemphillian age from Mulberry Canyon, near Goodnight, in the Texas
Panhandle. Gidley (1907) described more complete material (par-
ticulary a well-preserved skull, AMNH 10584) of what he called
Neohipparion lenticularis from older deposits of Clarendonian age in
Donley County of the Texas Panhandle. In Osborn's (1918) monograph
on the fossil Equidae, he listed AMNH 10584 as the neotype of Hip-
parion lenticulare [sic], but as Cope's original type specimens were
never lost, designation of a neotype was not necessary. Matthew and
Stirton (1930) refer hipparion material from the late Hemphillian Cof-
fee Ranch locality in the Texas Panhandle to Hipparion lenticularis.
 The recognition of the species "Hipparion" or "Nannippus" len-
ticularis is difficult because of the lack of well-preserved specimens
from the type locality. As envisioned by some workers, the broad
definition of this species that includes Clarendonian through latest
Hemphillian material is certainly open to question. Thus it is difficult
to defend an ancestral-descendent relationship for "N" lenticularis
and N. phlegon until the former species becomes better defined.
 It should also be noted that in Sondaar's (1968) discussion of the
equid manus, he stated that (p. 69): "There are smaller Hipparion-like
animals that do not belong to the genus Nannippus, for example the
species lenticulare [sic], which do not have the generic characters."
This statement suggests that the species "N." lenticularis and N.
phlegon, the latter of which is the genotypic species of Nannippus, are
not very closely related based on an analysis of postcranial remains.
 We suggest the hypothesis that Nannippus minor, N. beckensis,
and N. phlegon are relatively closely related. N. minor is best known
from Mio-Pliocene deposits of central and northern Florida (Sellards
1916, Simpson 1930), and it has also been described from Georgia
(Voorhies 1974)', Texas (Akersten 1972), and Chihuahua, Mexico
(Lance 1950, Mooser 19682). It should be noted that the holotype of N.
minor, FGS 5867, from the Bone Valley district, has been lost since
about the 1920's (see original description in Sellards 1916). We
designate here the neotype of N. minor, UF 17570, consisting of left
P3-M3 and right M2-M3 from Palmetto Mine in the Bone Valley district,
Polk County, Florida (Fig. 15, Table 11).
 Dalquest and Donovan (1973, also see Dalquest 1978) described a
new species, Nannippus beckensis, from the early Blancan Beck Ranch

'Leidy (1860) described a small and poorly known N minor-like horse, "Hipparion" venustum, from the Ashley River
of South Carolina.
'Nannippus aztecus, described by Mooser (1968) from the Ocote L. F. of Mexico, is probably a junior synonym of N.
minor Waldrop 19711.