OLDER POTOMAC OF VIRrrlNIA AND MARYLAND. 527 



Fossil, I'l.ANTS UtOSl IIIK (JI'KKNS ( IIAI'KI, KOAII. 



[PI. LXXX, near No. l.n.| 



On May 11, 1S97, Professor Ward collected, in a cuttiii<!; foi- the 

 electric railroad which begins a few steps beyond the crossing of the 

 Queens Chapel I'oad and extends northeastward foi' a distance of several 

 hundrefl \ ards, a specimen in counterparts of a small leafy twig belonging 

 to Sphenolcpidmm Sternbcryianuni densifolimu. It occurs in typical 

 iron-ore rock of a dark-reddish color, differing scarcely at all from that 

 yielding the fossil plants at the Langdon locality, which is onh' a short 

 distance from there. The age is evidently the same. 



LOCALITIES IN MARYLAND. 

 KdSSIl, I'l.ANTS KIKOI liOSIKKS KM KF, KOHT H»»TK. MAKVI.AXD. 



[PI. LXXX, No. 148.] 



Rosiers Bluff forms the bank of the Potomac River above Fort 

 Foote. The fossils are found 200 yards below Notley Hall wharf, and 

 about .30 feet aljove the water, on the Fort Foote reservation (see 

 pp. 373-.375). The plant-bearing stratum is 4 or 5 feet thick and is 

 compo.sed of partly indurated sand interstratified with layers of clay. 

 The material is lithologically similar to that which yields the fossils at 

 the 72d Milepost in Virginia. The fossils occur in a similar manner and 

 are in the main the same species as those of the Virginia locality, so that 

 there can be no doubt that the horizon is that of the Aquia Creek series. 

 The better specimens occur in the clay. This is sandy and has poor 

 cleavage. It tends to break up into lumps, so that the plants can rarely 

 be obtained in specimens as large as they are contained in the clay. 

 They seem, however, to have been in many cases much comminuted 

 before entombment. The locality was discovered by Professor Ward on 

 June 13, 1891, but the principal collection was made by him and Mr. 

 David White on November 25, 1891. As these collections were both 

 made at the same place, no attempt will be made to distinguish the 

 specimens obtained at the two dates except in the case of the figured 

 types. The specimens of Sapindopsis are the largest that are found 



