88 FLORIDA GEOLOGICAL SURVEY-EIGHTH ANNUAL REPORT. 
the base of the tooth contained the gray sand characteristic of the 
Alum Bluff formation. The tooth, as may be seen by the illustra¬ 
tions, is moderately hypsodont and has a coating of cement. The 
metaconid and metastylid are distinctly separated. The tooth is 
but little worn and may be referred with confidence to the genus 
Mery chip pus. 
Professor J. C. Merriam, who has compared this tooth with 
the horses of the western United. States contained in the Univer¬ 
sity of California collection, has kindly supplied the following 
notes: 
Your tooth, No. 173, most closely approaches the lower dentition of one of 
our horses from the recently discovered fauna occurring in beds crossing the 
summit of the Southern Sierra of Tehachapi. One of these species I have con¬ 
sidered the most primitive known Merychippus. * * * I will say in conclu¬ 
sion that your specimen No. 173, is very much more progressive than any Oligo- 
cene horse known to me. It is certainly very different from our uppermost John 
Day horses. Your specimen is also more progressive than any horse certainly 
referred to the lower Miocene of North America. Our fauna from the Teha¬ 
chapi is presumably middle Miocene, but it might possibly be the uppermost por¬ 
tion of the lower Miocene. I should judge that the horizon from which tooth 
No. 173 came is somewhere near the lower portion of the middle Miocene, un¬ 
less this is a very unusually advanced type in an old formation or an unusual sur¬ 
vival of an old form in a late formation. 
The specimen is No. 173 of the Florida Survey collection. The 
measurements are as follows: Greatest anteroposterior length, 17 
mm.; width 7 mm. The species is no doubt new although it is de¬ 
sirable to secure additional material to serve as a type before nam¬ 
ing the species. 
Since writing the above the writer has received through Mr. 
C. C. Ruprecht, Manager of the Fuller’s Earth Company, a lower 
molar of Merychippus from the fuller's earth mine at Midway. As 
in the tooth first obtained the metaconid and metastylid are dis¬ 
tinct. The tooth is moderately hyposodont and has a coating of 
cement. The height of the crown of the tooth which is slightly 
worn is 16 mm.; the transverse measurement is 10 mm.; the antero¬ 
posterior measurement is 15 or 16 mm. 
CANIDAE. 
MESOCYON? IAMONENSIS SP. NOV. 
PI. II, fig. II. 
A d.og from the Griscom plantation is represented by a single 
specimen, in which is preserved the right upper sectorial and right 
