A FOSSIL PORPOISE FROM THE CALVERT FORMATION 



OF MARYLAND. 



By Remington Kellogg, 

 Of the Bureau of Biological Survey, United States Department of Agriculture. 



INTRODUCTION. 



Our knowledge of the fossil cetacean fauna of the Calvert forma- 

 tion has hitherto been and still is very imperfect, notwithstanding 

 the description of a number of forms by E. D. Cope. Until lately 

 imperfect vertebrae represented our entire knowledge of most of 

 the cetaceans described from this formation. Notwithstanding the 

 recent explorations of the Calvert Cliffs and the acquisition of a 

 number of skulls, detailed information as to the zonal range of the 

 cetacean fauna is still wanting. The exact localities for the fossil 

 cetaceans described by Cope and collected by James T. Thomas in 

 Charles County, Maryland, have never been published. In conse- 

 quence the zonal position of most of these specimens will probably 

 remain unknown, unless subsequent discoveries show that some of 

 the fossil cetaceans are limited in their geologic range to one zone. 

 It is very unlikely that any cetacean had such a short geologic range. 



The collection of fossil cetaceans in the United States National 

 Museum includes a fairly representative assemblage of the cetaceans 

 known to have frequented the Chesapeake embayment during the 

 interval in which the Calvert formation was deposited. Most of 

 the types of fossil cetaceans necessary to a complete understanding 

 of this material as well as additional specimens from Tertiary marine 

 deposits of North America have been studied. The object of the 

 present paper is to describe a fossil porpoise collected by Norman H. 

 Boss on one of his trips to the Calvert Cliffs on the western shore of 

 Chesapeake Bay, Maryland. 



For the privilege of describing this fossil cetacean I am indebted 

 to C. W. Gilmore and J. W. Gidley, of the Division of Vertebrate 

 Palaeontology, United States National Museum. For permission to 

 examine types of fossil and living cetaceans I desire to extend my 

 thanks to Dr. Witmer Stone and James A. G. Rehn, of the Academy 



No. 2482 — Proceedings U. S. National Museum, Vol. 63. Art. 14. 



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