EASTERN AND SOUTHERN UNITED STATES. 
127 
and, likewise, the single species described by Searles.AVood from the older Tertiaries 
of England is a lower Eocene form. 
If such comparisons are of any value stratigraphically we may fairly look upon the 
Maryland Eocene deposits — the Piscataway sands below, and the Marlborough rock 
above — as representing a horizon nearly equal to that of the Thanet sands of England 
and the Bracheux sands of the Paris basin, or of the British Bognor rock (= London 
Clay).* In either case they would be near the base of the Eocene series. 
In the scale of the American series as exhibited in Alabama they would occupy 
a position probably near the base ofjhe “Buhrstone,” or possibly even lower, as the 
equivalents of the beds exposed on Bashia Creek, and Ca\e and Knight’s Branches 
(“Eo-Lignitic”). 
Miocene. — All the rest of the State southeast of the Eocene line, except such 
parts as may be covered by post-Plioceiie deposits — Worcester, Wicomico, and portions 
of Dorchester and St. Mary’s Counties — belongs to the Miocene formation. As in 
the case of New Jersey, no satisfactory evidence has as yet been brought forward 
proving the existence in the State of the Pliocene. 
In a former paper t I have, attempted to show that the po.st-Eocene Tertiary 
deposits of this State are divisible into two groups — an older and a newer, one of which 
— the newer — is unequivocally Miocene, and the other, possibly, Ohgocene; both 
belong to a period antedating the principal post-Eocene deposits of the States of North 
and South Carolina. The deposits of the older group, which I have since designated 
as the “ Marylandian,” X and have recognized as constituting the Lower Atlantic 
Miocene of the American coast, are best exhibited in the oyster banks, ri.sing a few 
feet above tide-water, in Anne Arundel County, along the western shore of the Chesa- 
peake, in the exposure of Calvert Cliffs, and in the Perna beds of the Patuxent River 
near Benedict. 
Localities of the newer group are found at or near Cove Point, Calvert County, 
the Patuxent River, below and above Benedict (in the deposits overlying the Perna 
beds), and at numerous points along the St. Mary’s River, in St. Mary’s County. The 
proportion of recent species in the fossil fauna is here very much higher than in the 
deposits of the older group, and clearly indicates a considerable interval between the 
periods of the respective depositions. Beds belonging to the newer period, which I 
have elsewhere correlated with the principal Miocene deposits of Virginia (tlie 
“Virginian”), also occur on tlie East Shore, at Easton, on the Choptank, ivhere the 
molluscan fossil fauna corresponds very closely with that observed on the west bank of 
the Patuxent. Connecting the points where the two series of deposits occur, it will 
* The similarity existing between the Marlborough and Bognor rooks has been pointed out by Conrad (Proc. 
National Institution, p. 173, 1841'. 
\ “X the^RettW^Ages^aud'ciLsification of the post-Eocene Tertiary Deposits of the Atlantic Slope,” 
Proc. A. N. S., June, 1883. 
