Maryland Geological Survey 93 



Fauna. — This member has yielded most of the prolific fauna described 

 from the Oriskany formation of Maryland. The uppermost beds at 

 Ridgely, West Virginia, have furnished the local collectors of Cumberland 

 with many fine fossils. Mr. Andrews, however, obtained the specimens 

 described by Hall mainly from two quarries, now abandoned, in the city 

 of Cumberland. One of these is in Green Street, below the Episcopal 

 Church, and the other is in the rear of the German Lutheran Church. Both 

 quarries are in the upper 75 feet of the Oriskany. In the Green Street 

 quarry the Marcellus shales plainly mark the top of the formation. At 

 these localities, however, particularly at the one back of the German 

 Lutheran Church on Shriver's Hill, the excavation has been carried far 

 below the surface into layers that are not shown in West Virginia. This 

 serves to explain why certain forms like Spirifer cumherlandice, S. trihulis, 

 etc., are now seldom found about Cumberland. 



At this locality a peculiar condition of leaching of the Oriskany has 

 made it possible to obtain fossils completely weathered out of the inclos- 

 ing rock, as siliceous pseudomorphs. This method of preservation is 

 restricted to Cumberland and the reason for it will be shown presently. 

 So many of these delicate fossils have been sent out by local collectors that 

 it has become a general belief that they can be procured anywhere in the 

 Oriskany of Maryland. Regarding this state of preservation Hall ' wrote : 



" While in the State of New York the accessible portions of the rock 

 furnish us for the most part with casts of its fossils, or, if beyond the reach 

 of weathering, with a compact mass of calcareous sandstone in which the 

 fossil remains are closely imbedded, we find, in Maryland and some parts 

 of Virginia, that in the friable sandstone the shells are entirely silicified 

 and quite free from adhering stone, so that the exterior markings and 

 internal structure are perfectly preserved ; the interior being quite hollow, 

 or filled only with loose sand. In these localities, not only do we find the 

 cavities of large gasteropods with no more adhering matter than those of 

 the Tertiary sands, but more unfrequently the delicate internal apparatus 

 of the Brachiopod is almost entirely preserved." 



^Pal. New York, vol. iii, 18.59, pp. 401. 402. 



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