416 PROCEEDINGS OP THE ACADEMY OF [18«1. 



A REVISION OF THE CIS-MISSISSIPPI TERTIARY PECTENS OF THE 

 UNITED STATES. 



BY ANGELO HEILPRIN. 



In the accompanying notes the author has attempted to give a 

 complete list of all the Pectens thus far described from the tertiary 

 deposits of the United States east of the Mississippi River, 

 indicating, as far as possible, their range in time and their 

 geographical distribution. The rather hap-hazard method in which 

 the tertiary palaeontology of a great portion of the United States 

 has thus far been treated has rendered the statement of this last 

 a matter of great difficulty, and doubtless the range, both in time 

 and space, of many of the species herein enumerated, will require 

 emendation when more accurate data will have been brought 

 directly from the field itself. 



The titles of the various works quoted are indicated by the 

 following abbreviations : — 



J. A. N. S. Journal of the Academy of Natural Sciences of Phila. 



Proc. A. N. S. Proceedings of the Academy of Natural Sciences. 



A. J. Science. American Joui-nal of Science and Arts. 



A. J. Conchol. American Journal of Conchology. 



Mioc. Foss. Conrad's "Fossils of the Medial Tertiary of the United 



States." 

 Syn. Org. Rem. Morton's " Synopsis of the Organic Remains of the 



Cretaceous Group." 

 Plioc. Foss. " Pleiocene Fossils of South Carolina," by Tuomey and 



Holmes. 



The generic names placed in parentheses indicate the names 



under which the given species apper in the " Smithsonian Check 



Lists " of 1864 and 1866. 



Eocene. 

 P. anisopleura Conr. N. Car. 



Kerr, "Geol. Survey of North Carolina," 1875, Appendix, p. 18. 



P. calvatus Mort. (Camptonectes) S. Car. 



Syn. Org. Remains, p. 58 (Jacksonian) . 



P. Carolinensis Conr. N. Car. 



Kerr, "Geol. Survey of North Carolina," 1875, Appendix, p. 18. 



T P. Claibornensis Conr. (Camptonectes). Ala. 



Smithsonian Check List, 1866. 



