100 THE CAMBRIAN AND ORDOVICIAN DEPOSITS OF MARYLAND 



does not leave any residual chert upon weathering and its contained 

 fossils unfortunately do not become silicified. As a result, their preserva- 

 tion is not of the best and natural sections in the rock or poor casts are the 

 rule. The granular beds associated with the edgewise conglomerate of 

 the upper part of the Stonehenge limestone is the most favorable place 

 for collecting the brachiopod and gastropod shells, some of these beds 

 being fairly crowded with specimens of Dalmanella wemplei. The 

 cephalopods and trilobites have in the main been found in reef-like 

 structures in the lower Stonehenge and their occurrence is therefore quite 

 sporadic. At one point a stratum will exhibit numerous cross-sections 

 of fossils, but a foot or two away where the reef material composed of a 

 very fine edgewise conglomerate has disappeared, no trace of a fossil can 

 be found. 



The following table gives a list of the Stonehenge fauna and shows the 

 distribution of the species in the Kittatinny limestone (upper part called 

 the Coplay limestone) of New Jersey and the Tribes Hill limestone of 

 New York, formations with which on strati graphic and paleontologic 

 grounds, the Stonehenge is correlated. 



LIST OF STONEHENGE LIMESTONE FOSSILS SHOWING DISTRIBUTION 



