DESCRIPTION OF A NEW GENUS AND SPECIES OF FOSSIL 

 SEAL FROM THE MIOCENE OF MARYLAND. 



B}'^ Frederick W. True, 



Head Cnrdtor, T>e}t(irfiinnt af Biologji. 



While engaged in collecting fossils for the United States National 

 Museum from the Miocene cliffs bordering the Chesapeake Bay in 

 (Calvert County, Maryland, known as the ''Calvert Cliff's," I found a 

 few fossil bones which are unmistakal)ly those of seals. The.se 

 bones, as I have already remarked in a recent nund^er of Science," are, 

 so far as I am aware, the ffrst authentic renigins of fossil seals found 

 in America. They consist of a nearh^ perfect humerus, the va<lius of 

 a young individual (without epiphyses), a fragment representing the 

 proximal end of the conjoined tibia and ffbula, and an imperfect lum- 

 bar vertebra. The humerus is light gray in color, ])ut the other hones 

 light brown. 



In the same locality with these remains was found a larger humerus, 

 which at ffrst I thought might be that of a seal, but on closer examina- 

 tion it appears to be that of a sirenian, belonging, perhaps, to the 

 Halitheriidte and allied to ILeta^ryfheriuin. It is broken and consider- 

 ably waterworn, so that its original form can not be certainly deter- 

 mined. For that reason, I do not think it necessary to devote any 

 further attention to it in the present connection, though it appears to 

 represent a sirenian type not hitherto found in America. It is figured 

 on Plate LXXVI, ffg. 4 (Cat. No. 5360, U.S.N.M., Vert. Paleon.). 



The smaller humerus already mentioned, though lacking the head 

 and the extremity of the lesser tuberosity, is so well preserved that 

 its characters are plainly discernible. It obviously represents a spe- 

 cies belonging to the family Phocidse, and a genus allied to rhvai, but 

 is not identical with that genus nor any other existing genus of the 

 familv. As a means of individualizing it, I propose to establish for 

 it the new genus Leptophoca. The following are the characters as far 



as can be drawn from the humerus: 



• « Science, n. s., XXII, p. 794, Dec. 15, 1905. 



Proceedings U. S. National Museum, Vol. XXX-No. 1475. 



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