UPPER CRETACEOUS OSTRACODA FROM NORTH CAROLINA 



By 

 Philip Monroe Brown 1 



Abstract 



Fifty-six species of Upper Cretaceous Ostracoda from ten exposures in North Carolina and one 

 exposure in South Carolina are described and illustrated. Twenty-seven of the species are new. The 

 following genera, one of which is new, are represented in the material : Cytherella Jones, Cytherel- 

 loidea Alexander, Bairdia McCoy, Bairdoppilata Coryell, Sample, and Jennings, Cytheridea (Haplo- 

 cytheridea) Stephenson, Cytheridea (Clithro cytheridea) Stephenson, Alatacythere Murray and Hussey, 

 Brachycythere Alexander, Trachyleberis Brady, Platycythereis Triebel, Protocythere Triebel, Prog- 

 onocythere Sylvester-Bradley, Cytheropteron (Cytheropteron) Sars, Cytheropteron (Eocytheropter- 

 on) Alexander, Velarocythere Brown, Cytherideis Jones, Monoceratina Roth, Loxoconcha Sars, Ortho- 

 notacythere Alexander, Cytherura Sars, and Eucytherura Muller. A checklist showing relative abun- 

 dance of specimens in outcrop and denoting the occurrence of species in strata penetrated by water 

 wells is included. 



1 Geologist, Ground Water Branch, U. S. Geological Survey, Raleigh, N. C. 



Introduction 



This paper is a result of studies undertaken to 

 establish paleontologic control for the subsurface 

 separation of the Upper Cretaceous Black Creek 

 and Peedee formations in the North Carolina 

 Coastal Plain. Ground-water investigations had 

 shown the two formations to be major aquifers 

 and distinct hydrologic units, but their lithologic 

 similarity precludes their visual separation in 

 well cuttings. The Ostracoda were chosen as the 

 paleontologic control because of their apparent 

 tolerance to variable environmental changes, re- 

 sulting in a wide distribution of species in vari- 

 able lithofacies over relatively wide geographic 

 areas. All species described in this paper are from 

 outcrops of Cretaceous sediments. A checklist (fig. 

 2) notes species that have been recognized in well 



cuttings. Information relative to the occurrence 

 of the species in the subsurface is taken from a re- 

 port by the writer entitled, "Well logs from the 

 North Carolina Coastal Plain," which is to be 

 published by the Division of Mineral Resources 

 of the North Carolina Department of Conserva- 

 tion and Development after the publication of 

 this report. 



This investigation was made by the United 

 States Geological Survey in financial cooperation 

 with the North Carolina Division of Mineral Re- 

 sources. The work was done under the general 

 supervision of A. N. Sayre, Chief, Ground Water 

 Branch, U. S. Geological Survey, and J. L. 

 Stuckey, State Geologist of North Carolina, and 

 under the immediate supervision of H. E. Le- 

 Grand, district geologist of the Ground Water 

 Branch for North Carolina. 



