432 The Upper Devon iax Deposits of Marylaxd 



only, in eastern and central New York. These include Bucanopsis maera, 

 Loxonema styliolum, Sandhergergoceras chemungensis, and Mantkoceras 

 patersoni. They also resemble the Cayuta member in being much more 

 fossiliferous than the overlying strata. 



The lovper shale and sandstone beds are succeeded by a massive conglom- 

 eratic sandstone containing the Tropidoleptus carinatus fauna at many 

 places. There is also a similar recurrence of the Tropidoleptus carinatus 

 fauna at the top of the Cayuta member of New York. In Maryland this 

 fauna has been observed chiefly in the central part of the area and contains 

 the following species, all of which occur in the corresponding zone in New 

 York : Tropidoleptus carinatus, Spirifer marcyi var. superstes, Rhipido- 

 mella vanu^emi, Camarotcecliia contracia, Ambocoelia urribonata, Spirifer 

 mesacostalis. The recurrence of a fauna of Hamilton type above the base 

 of the Chemung, in a position similar to that in which it occurs in New 

 York is of great interest and still further indicates the similarity of the 

 conditions under which sedimentation took place in both areas and the 

 probable equivalency of these horizons. A recurrence of the Tropidoleptus 

 carinatus fauna corresponding to its recurrence near the base of the Che- 

 mung in New York has not been assuredly observed in Maryland. The 

 Spirifer disjunctus fauna has, however, been found at the base of a section 

 exposed in the axis of a small anticline, situated a short distance east of the 

 house of Mr. Cheney 2.2 miles northeast of Pratt, on the road leading to 

 Pifteenmile Creek. An abundant development of the Tropidoleptus 

 carinatus fauna may be seen on the hilltop a little over 100 feet higher 

 stratigraphically, which strongly suggests the fauna in the upper zone of 

 the Parkhead, while the undoubted upper Tropidoleptus carinatus fauna of 

 the Chemung is seen in different associations in a conglomerate on the 

 hills to the west. It is hence possible that the Spirifer disjunctus fauna 

 may occur below the top of what has been considered the Parkhead mem- 

 ber in this locality, in which case the upper zone of that member may 

 represent the lower recurrence of the Tropidoleptus carinatus fauna in 

 the Chemung of New York. The stratigraphic relations are, however, too 

 obscure at this place to permit confident conclusions, while the Spirifer 



