70 TRANSACTIONS OF THE [1890 



The brown powdery sand which cloaks the upper parts and 

 sides of so many of the high hills, all the way across this wide 

 belt from the Patapsco to the Severn, is usually indurated into 

 sandrock, either on the surface or a short distance beneath it, . 

 and this material may often be traced with a distinctly gradu- 

 ated regularity down to the base below where it is composed of 

 the highly colored greensand. 



It seems remarkable that the bluish-black, or true shell- 

 marl of the Eocene, should fail to be present in this section of 

 country. Small patches of the whiter and less ferruginated 

 shell-rock, such as that seen beneath the green clay-marl of the 

 country west of the Severn river, have been reported as oc- 

 curring in the region near the mouth of the Magothy river ; 

 but no continuous stratum of this nature has yet been discov- 

 ered in the uplands of these necks of land. Nevertheless, fos- 

 sils of the iron-stained varieties abound, and the soil in some 

 places, as we go towards the Severn river, is loaded with the 

 fossil shells, or their casts and moulds. Denudation, after the 

 deposition and uplift of the Eocene beds of this part of the 

 country, has cleared oif a thickness of many feet of surface 

 which formerly rested above the strata containing the fossils. 

 This removal of materials has also occurred over extensive 

 tracts, now composing large fields, throughout which the shells 

 may be seen either upon or only a little way beneath the sur- 

 face of the soil. The proofs of this may frequently be observed 

 in the adjoining hillsides, where the fossils rest covered up 

 beneath many feet of the ferruginous marl. 



In the city of Annapolis we find an interesting example of 

 the way in which denudation has cleared away the surface from 

 above the fossil shells. There, as on the opposite side of the 

 Severn river, aqueous agencies have lowered some of the hills 

 to a level of not more that 30 feet above the tide, and upon the 

 very surface of the denuded level the fossil shells formerly 

 rested in vast numbers. Even now, after so much of the area 

 has been occupied by buildings, remnants of the old condition 

 of things persist on the meadows which extend beyond the 

 houses in the western part of the city. But as we proceed up 

 the railroad, at occasional intervals the same kinds of fossils 



