90. FLORIDA GEOLOGICAL SURVEY-EIGHTH ANNUAL REPORT. 
astragalus with the astragalus of Lcptomcryx contained in the Na¬ 
tional Museum from Hat Creek basin, Siox County, Nebraska, 
representing the Oligocene, indicates no pronounced differences, 
and the specimen is with little doubt to be referred to that genus. 
The Florida specimen is possibly somewhat wider than is the as¬ 
tragalus of the species with which comparison was made. The di¬ 
mensions of the astragalus are as follows : Greatest length 13 mm.; 
greatest width 7 mm. While this astragalus may represent an 
animal generically distinct from Lcptomcryx, it may nevertheless 
he safely referred to the family Hypertragulidae. 
INDETERMINATE FOSSILS. 
The remaining fossils include: A fresh-water turtle, repre¬ 
sented by fragments of the carapace; a crocodilian, represented by 
teeth, parts of the jaw, vertebrae and dermal plates; a shark, rep¬ 
resented by teeth, and an eagle ray, represented by parts of teeth; 
fish scales and vertebrae are also numerous. The turtle and alliga¬ 
tor, as well as the scales of fish, have been found at Midway in 
place in the fuller’s earth stratum. The other fossils are derived 
chiefly from above the fuller's earth or from a sandy matrix be¬ 
tween the two fuller's earth strata. The presence of the vertebrate 
fossil's in the fuller’s earth deposit is evidence of the near shore 
origin of this formation. 
AGE OF THE ALUM BLUFF FORMATION. 
The type locality of the Alum Bluff formation is at Alum Bluff 
on the Apalachicola River in Liberty County. With the exception 
of the incoherent sands at the top, the entire exposure at Alum 
Bluff was referred by Langdon, who first described the section to 
the Miocene.* The term “Alum Bluff beds" was proposed by 
Dali in 1892!, and was defined as including the “unfossiliferous 
sand and clay strata intervening between the Chipola marl and the 
upper fossiliferous bed at Alum Bluff.” At that time the deposits 
were referred to the “old Miocene,” in contrast to the newer or 
Chesapeake Miocene, found at a higher level in the same section. 
*Some Florida Miocene; by Daniel W. Langdon, Jr., Amer. Journ. Sci., 
(3) xxxviii, pp. 322-324, 1889. 
t U. S. Geol. Surv. Bull. 84, p. 122, 1892. 
