202 TRANSACTIONS OF THE WAGNER FREE 



uiidenuded region between St. Augustine and Chesapeake Bay the Pliocene, 

 if any, was to be looked for. 



The deposits in question consist in general of isolated patches of marl' 

 lying in depressions or over low areas of the Eocene or Cretaceous rocks. 



These marls differ from the Miocene beds of Virginia in the greater 

 percentage of lime which they generally contain. Paleontologically the 

 difference was supposed to be equally great. According to Tuomey (op. cit., 

 p. 183) and Heilprin (op. cit., pp. 51 to 53 and 60 to 61), the proportion of 

 recent to extinct species in the Carolinian fauna is more than double that 

 which occurs in the Miocene of Virginia. Though Holmes,' Ruffin,^ Lyell,^ 

 and Conrad^ regarded the Carolinian beds as Miocene, the facts above 

 mentioned led Tuomey" to refer the beds to the Pliocene — a view maintained 

 later by Tuomey and Holmes in their work on the Pliocene of South Carolina.'' 

 In view of the presence of sundry characteristic Miocene species in the fauna 

 described by Tuomey, the most prominent student of our Tertiaries, T. A. 

 Conrad, refused to regard the beds as other than Miocene, though possibly as a 

 later series than the Miocene of Virginia and Maryland, and this opinion has 

 been accepted by subsequent students until very recently. In short, the fauna 

 described by Tuomey and Holmes has been regarded as a transition fauna, or 

 " Upper Atlantic Miocene,''^ up to within the past few years. The question as 

 to whether it was a natural fauna at all was not, apparently, raised by any 

 one ; and, until the discovery of the Caloosahatchie beds, it could not have 

 been successfully raised (except by a re-examination of the beds on the spot) 

 for want of an indisputable standard of comparison. 



Dana, in his " Manual of Geology,"^ hardly touches upon the question, 

 but, dividing the period of the American Tertiary into epochs of time, he 

 names the last " Sumter, or that of the beds of Sumter and Darlington 

 districts of South Carolina, in which forty to sixty per cent, of the fossils are 

 living species ; called also Pliocene." To this supposed fauna Heilprin,'" in 

 1884, applied the name of " Carolinian or Upper Atlantic Miocene," in contra- 

 distinction to the Miocene beds of Virginia and Maryland, comprehended in 

 their time relations by the " Yorktown epoch of Dana." 



In his study of the Floridian Tertiary, and the comparisons which it 

 made necessary, the writer was rapidly forced to the conclusion that the 

 fauna catalogued and illustrated by Tuomey and Holmes in their " Pleiocene 

 Fossils of South Carolina " was not a true fauna at all, but a confusion of 



1 Tuomey, Geol. of South Carolina, p. 171, ISiS ; Heilprin, Tertiary Geol. of the U. S., p. 21, 1884. 

 •2 Notes on the Geol. of Charleston, S. C, p. 4, 1849. 

 " Agricultural Survey of South Carolina, p. 27, 1843. 

 " Quarterly Journal Geol. Soc. of London, Vol. I., p. 413, 1845. 

 " Medial Tertiary Formation of the U. S., Introduction, page T., 1838. 

 » Geol. of South Carolina, p. 171, 1848. 



' Pleiocene Fossils of South Carolina. Charleston, S. C. Russell and Jones, 1857. Introduction, pp. ix.-x. 

 » Heilprin, Tert. Geol. 0. S., pp. 64-66, 1884. 

 ' Edition of 1863, p. 506. 

 '» Tertiary Geol. U. S., p. 67, 1884. 



