1922] Kellogg: Pinnipeds from Miocene and Pleistocene Deposits 71 



old as Leptophoca lenis. This phocid was based upon a humerus found 

 in the Calvert Cliffs, Calvert County, Maryland, between Chesapeake 

 Beach and Plum Point. True, 90 in his description of Leptophoca lenis, 

 pointed out that the humerus is more slender than in any existing 

 genus of seals. The peculiar features of this humerus are shown in 

 the following extract from True's paper. 



An extinct pliocine pinniped mammal, having- the humerus more slender than 

 in any existing genus of seals. Deltoid ridge well developed and broad at the 

 upper, or proximal, end, but narrowing rapidly below and terminating in a thin 

 edge, which, at a point considerably below r the middle of the bone, joins at an 

 obtuse angle the ridge running to the inner edge of the trochlea. Lesser tuberosity 

 only moderately developed, the bicipital groove between it and the greater tubero- 

 sity very narrow relatively. Entopicondylar foramen present. 



Leptophoca lenis was probably about the size of Phoea groenlandica. The 

 humerus of the latter, while of almost the same length, is much thicker, and the 

 deltoid ridge, as in all existing seals, is thick distally as well as proximally. The 

 lesser tuberosity is much more massive than in Leptophoca and is separated from 

 greater tuberosity by a very wide bicipital groove. 



It is noteworthy that Sir Charles Lyell 97 in the course of his 

 geological investigations on Martha's Vineyard, Massachusetts, dis- 

 covered a canine tooth in the Gay Head Miocene which was identified 

 by Professor Owen as allied to Cystophora proboscidca. 



In the Antwerp basin of Belgium are marine beds of Miocene and 

 Pliocene age which have already yielded a great variety of fossil 

 pinnipeds as well as cetaceans. Van Benede.n 98 lias described and 

 figured two forms, Prophoca roussemii and Prophoca proxima, from 

 the black sands of this basin. Abel' 19 in the course of his studies on 

 the cetaceans of the Antwerp basin referred this black sand series to 

 the Bolderian, equivalent in time to the Upper Miocene. More recently 

 Hasse 100 has adduced evidence to prove that the black sands belonged 

 to the Diestian stage. 



so True, P. W., Description of a new genus and species of fossil seal from the 

 Miocene of Marvland. Proc. U. S. Nat. Mus., vol. 30, no. 1475, pp. 836, 837. 

 1906. 



°7 Lyell, C, On the Tertiary strata of the Island of Martha's Vineyard in 

 Massachusetts. Proc. Geol. Soc. London, vol. 4, no. 92, p. 32. 1846. 



98 Van Beneden, P. J., Bull. Acad. Roy. Sci. de Belgique (2), vol. 41, no. 4, 

 pp. 801-802, 1876. Ann. Mus. Boy. Hist. Nat. de Belgique, vol. 1, pt. 1, pp. 79-81, 

 pi. 18, figs. 1-16. 1877. 



99 Abel, O., Les dauphins longirostres du Bolderien (Miocene Superieur) des 

 Environs d'Anvers. Mem. Musee Boy, Hist. Nat. de Belgique, Brussels, vol. 1, 

 pt. 1, p. 43. 1901. 



100 Hasse, G., Les sables noirs dits Miocenes bolderiens a Anvers. Bull. Soc. 

 Beige de Geol., de Paleont. et d 'Hydrol., Proces Verbal, vol. 23, pp. 353-361. 1910. 



