TRANSACTIONS OF WAGNER 

 1560 



TERTIARY FAUNA OF FLORIDA 



In the working season of 1900 Mr. T. Wayland Vaughan, of the United 

 States Geological Survey, visited Bainbridge, Decatur County, Georgia, and 

 was fortunate enough to discover a rich coral fauna near Russell Spring, four 

 miles below Bainbridge, on the Flint River.* By means of this fauna he was 

 enabled to make a direct correlation between the lower Chattahoochee beds 

 (lying unconformably on an eroded surface of the Orbitoidal limestone at 

 Russell Spring) and the Oligocene fauna of the island of Antigua. The pres- 

 ence in both of the characteristic genus Orthaulax was proved by material 

 received from Antigua and Bainbridge, and the species appears to be not that 

 of the Chipola marls (0. Gabbi) or that of the St. Domingo Oligocene beds 

 (O. inornatus), but that of the Tampa silex beds (0. pugnax). Mr. Vaughan 

 suggests that the Oligocene reefs in the vicinity of Lares, Porto Rico, and of 

 the Serro Colorado, Curacoa, probably represent the same horizon. Those of 

 Bowden and at least part of those in St. Domingo are younger and correspond 

 more nearly to the Chipola marls and Oak Grove sands of the Floridian series. 

 The generally poor preservation of the Chattahoochee molluscan fossils makes 

 the aid of the corals all the more welcome and important. 



Pumpelly has shown f that at the base of the Chattahoochee there is an 

 eroded surface of the Orbitoidal limestone upon which rolled pebbles of the 

 limestone form a conglomeratic layer, upon which occur the reef corals. This 

 is also the result of Vaughan's observations. We have, therefore, a definite 

 unconformity for the base of the Chattahoochee. To determine its upper limit 

 further observations are necessary. The presence of the Tampa species of 

 Orthaulax at Bainbridge and Antigua points to the inclusion of the Orthaulax 

 bed in the Chattahoochee rather than in the Tampa or Chipola group, as I 

 formerly supposed. We have not yet any sufficient list of molluscan or other 

 invertebrate fossils from the Chattahoochee limestone. Mr. Vaughan's list of 

 corals is still awaiting publication, but of the main facts established by it and 

 above summarized there seems no reason to doubt. 



Professor G. D. Harris has determined that near Oak Grove, Florida, the 

 typical Grand Gulf sandstones " pass under the Oak Grove sands, thus indi- 

 cating that the sandstone is of approximately the same age as the Chatta- 

 hoochee." X This agrees with the earlier observations of E. A. Smith, who 

 says : " The barren Grand Gulf sands pass towards the east into the marine 



* See Science. N. S., xii., pp. 873-75. Dec. 7, 1900. 

 t Am. Journ. Sci., 3d Ser., xlvi., pp. 445-?. i89.3- 

 t See Bull. Am. Paleont., iii., No. 15, p. 70, 1902. 



