DESCRIPTION OF A NEW FOSSIL PORPOISE OF THE GENUS DEL 

 PHINODON FROM THE MIOCENE FORMATION OF MARYLAND 



By Frederick W. True, M.S., LL.D. 



For more than twenty years, the present writer has interested himself in 

 endeavors to accumulate in the National Museum a collection of specimens of 

 North American fossil cetaceans sufficient to afford at least a fairly accurate idea 

 of this portion of the extinct vertebrate fauna of America. The opportunities 

 and resources for this undertaking have not been extensive and it is only recently 

 that results of importance have been obtained. 



In the earlier years the present writer visited the Nomini Cliffs and other 

 points in Westmoreland County, Virginia, on the Potomac River, and collected 

 vertebrae and fragments from other parts of the skeleton, nearly all of which 

 were specimens which had been washed out from the cliffs and were picked up 

 on the shore of the river. In 1905 he began work along the Calvert Cliffs in 

 Calvert County, Maryland, on the west shore of Chesapeake Bay between 

 Chesapeake Beach and the mouth of the Patuxent River. In 1908 and 1909 

 he was assisted by several members of the staff of the National Museum, in- 

 cluding Mr. Wm. Palmer, Dr. M. W. Lyon, Jr., Mr. Norman Boss, and Mr. D. B. 

 Mackie. 



These later collections, in addition to vertebrae, teeth, humeri, etc., picked up 

 on the shore of the bay, include one nearly complete skeleton (collected by 

 Wm. Palmer), several skulls and portions of skulls (collected by F. W. True, 

 Wm. Palmer, and D. B. Mackie), and various bones found in the cliffs and cut 

 out by means of picks and knives. A considerable number of interesting speci- 

 mens were contributed by persons who had visited the cliffs from curiosity, or in 

 search of shells, sharks' teeth, etc. 



The collection now assembled includes remains which seem calculated to 

 throw important light on the fossil cetacean fauna of North America, and on 

 the evolution of this order of mammals, as well as to clear up to some extent 

 the obscurity surrounding the investigations of earlier writers, whose work 

 was based on very insufficient material. The present paper is intended as the 

 first of a series descriptive of the more important remains. As a preliminary, all 

 the available types of North American species heretofore described have been 

 examined. In this connection I wish to acknowledge, with very sincere thanks, 

 the liberality of the authorities of various museums and other institutions in 

 placing type-specimens in my hands for study, or allowing me access to them, 

 including The Academy of Natural Sciences of Philadelphia, Johns Hopkins 

 University, Goucher College, Harvard University, and the American Museum 



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