A NEW NAUTILOID CEPHALOPOD, EUTKEPHOCEKAS 

 SLOANI, FKOM THE EOCENE OF SOUTH CAROLINA. 



By John B. Reeside, Jr., 



Of the United States Geological Survey. 



Species of the genus Eutrephoceras are rare in the Tertiary de- 

 posits of the United States. Wliitfield^ described one, as Nautilus 

 cookana^ from the Shark River marl of New Jersey, probably of 

 middle Eocene age, but none, so far as the writer knows, has been 

 described from the Eocene of the southeastern United States. The 

 specimen on which this paper is based is therefore of considerable 

 interest, and, though it is perhaps not so complete as one might 

 wish a type specimen to be, most of its essential characters can be 

 made out and are worth recording for the benefit of future col- 

 lectors. 



The specimen was found in silicified marlstone at Perkins Bluff 

 on Black River, Georgetown County, South Carolina, by Earle 

 Sloan, of Charleston, South Carolina., then State geologist, and 

 listed as Enclimatoceras ulrichi White.^ It was borrowed from Mr. 

 Sloan by Dr. C. Wythe Cooke, of the United States Geological 

 Survey, in order to verify the identification, and when found to 

 differ from the type of E. ulrichi was placed in my hands for de- 

 scription. At Doctor Cooke's suggestion, Mr. Sloan has deposited 

 the specimen in the United States National Museum. 



Because of the supposed presence of ^'ricZima^OfjeraswZrwjAi, a Mid- 

 way species, the beds at Perkins Bluff, belonging to the Black Mingo 

 formation, were regarded by Sloan as of Midway age.^ However, 

 as the rock matrix of the type of Eutrephoceras sloani contains 

 impressions of a coral identified by Dr. T. W. Vaughan as 

 Haimesiastraea conferta Vaughan, a species ranging through the 

 Midway and Wilcox groups of Alabama, the geologic age of the 

 beds might be either Midway or Wilcox. 



1 Whitfield, R. P., Gasteropoda and cephalopoda of the Raritan clays and Greensand 

 marls of New Jersey : U. S. Geol. Survey Mon. 18, pp. 285-286, pi. 48, fig. 1 ; pi. 49, 

 fig.s. 4, 5, 1892. 



2 Sloan, Earle, Catalogue of the mineral localities of South Carolina : South Carolina 

 Geol. Survey, ser. 4, Bull. 2, p. 310, 1908. 



* Vaughan, T. W., in Willis, Bailey, Index to the stratigraphy of Nortli America : U. S. 

 Geol. Survey Prof. Paper 71, p. 732, 1912. 



No. 2518-Proceedings U. S. National Museum, Vol. 65, Art. 5. 



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