HILL: GEOLOGY OF JAMAICA. 185 
Beds of the Vicksburg horizon have not been discovered between 
Yucatan and the Mississippi. Agassiz} has reported the beds of the 
Vicksburg epoch as constituting a ridge along the southern peninsula 
of Yucatan, Orbitoidal and Nummulitic limestones form a belt of strata 
in Chiapas and Yucatan back of the later marginal coast formations. 
A. Agassiz's observations, notwithstanding Heilprin’s denial, have been 
confirmed by the moro recent explorations of Dr. Karsten, J. Felix, and 
H. Lenk.? These authorities show the existence of Orbitoidal and 
Nummulitic limestones in the vicinity of the ruins of Palenque and other 
localities, and prove according to them the existence of marine Eocene 
Strata of the Alpine Nummulitie and Orbitoidal limestone facies in Yuca- 
tan, Mexico. 
The only known locality of this formation around the margin of the 
Caribbean is in the uptilted beds at Guallava, Costa Rica, 150 feet 
above the sea, which Dall has identified from collections made by the 
writer, as reported in my work on the Isthmus of Panama. In Costa 
Rica at least, the Vicksburg beds are of an impure non-oceanie nature, 
occurring as in the Antilles above igneous derived rocks. 
Although the Bowden fossils are reported to have wide extent in the 
tropical region? by paleontologists, the formation has not been clearly 
defined stratigraphieally. According to Dall the molluscan element 
of the fauna is homotaxially equivalent to the Chipola, Tampa, and 
Ohattahoochee beds of Southern Florida, and oceurs also in Trinidad 
aud Curagoa. It also oceurs around the continental perimeter along 
the Carribbean side of the Isthmus of Panama, where the formation has 
been described by the writer as the Monkey Hill beds‘ of Panama and 
back of Chiriqui lagoon. There can be little doubt, however, that the 
Sediments of this age have considerable extent along the Talamancan, 
Panamie, and Colombian coasts of this general Isthmian region. 
The equivalents of this formation are known in Cuba, and its fossils 
from Haiti, It has great development along the north coast of Cuba 
especially towards the eastern end, where it is composed of the yellow 
clays and gravel beds called Miocene (after Dall) in tho writer's papers 
on that island," and is well developed at Matanzas, Nuevitas, Gibara, 
and Baracoa. I now have little doubt, in the light of later experiences, 
1 Three Cruises of the Blake, Vol. I. 
? Neues Jahrbuch für Mineralogie, 1895, Bd. TI. pp. 207, 208. 
3 Proc. U, S. Nat. Mus., 1896, Vol. XIX. p. 304, 
* 'The Geological History of the Isthmus of Panama, p. 176. 
* Notes on the Geology of the Island of Cuba, Cambridge, 1895. 
