1892] MARYLAND ACADEMY OF SCIENCES. 2()7 



of its deposits, or the elevation of the beds and domes of 

 clay upon which it lies. It stretches out north-east through 

 Maryland, ISTew Jersey, and a part of Long Island, in a belt 

 rarely more than three miles wide, but usually having a 

 width of not much more than one mile. It is cut apart by 

 the rivers and bays which traverse the region where it was 

 laid down, and it has suffered from local erosion in many 

 of its larger divisions. The superimposed drainage of its 

 surface, represented by numerous rivulets, creeks, and rain 

 troughs, now dried up or only occupied by small swamps 

 or cranberry bogs, was directed eastward, and probably 

 entered a series of landlocked sounds and bays extending 

 alone: the coast of the mainland. These bodies of water 

 might have been brackish, but none of their sediments have 

 yielded organisms which belong to salt water such as that 

 of the sea. This formation belongs specifically to the type of 

 freshwater deposits, carried from the mainland through 

 shallow drains out to the broader water, and dropped 

 there around the older clays which formed islands and 

 headlands after the close of the Potomac Period. The 

 material, consisting first of coarse, chiefly angular sand, 

 later of argillaceous sediment charged with vegetable re- 

 mains, was distributed by rapidly moving waters, which 

 seem to have successively risen and fallen, so as to deposit 

 alterna'ting thin layers of clay and find white sand, enclos- 

 ing the lignifying woody drift. Pyritous nodules and 

 coatings around lignite abound in many parts of the car- 

 bonaceous sandy clays ; and the filmy residue of leaves, to- 

 gether with twigs and seeds, occur in the laminae and 

 layers of the firmer clay members. Leaves of a Sa_pindus ; 

 Eucalpytus geinitzi Heer ; Liriodendron simjylex Newb. 

 Sequoia mnhigua Heer, and a Sassafras, besides many 

 unrecognizable forms of leaves, were found by the writer 

 in the layers of the alternating clay on both the west and 

 the south-west faces of the Gay Head clifi's. The specimens 



