393 The Upper Devonian Deposits of Maryland 



Au exposure occurs on tbe northeast side of the highway from Deer Park 

 to Altamont in descending the hill toward the small run. The rocks are 

 sliown in place and consist of olive shales and thin gray sandstones which 

 alternate with three zones of red argillaceous shales, the middle one being 

 partly arenaceous and about 5 feet thick. There are certain layers of the 

 rock which contain large numbers of Spirifer disjundiis Sowerby, 

 Produciella lachrymosa Hall, and other fossils. The lowest reds are at the 

 base of the small hill so that all the specimens of fossils occur above red 

 shales. This exposure, which is mapped on the geological map of the 

 Piedmont Folio as at the base of the Catsldll formation, is clearly in 

 the Chemung after the appearance of the red shales and is a favorable 

 one for studying the Chemung fauna. About 60 feet of rocks are exposed, 

 the greater part of which consist of olive colored, argillaceous, blocky 

 shales. 



Along tlie highway to the north of Deer Park are some exposures of 

 Chemung rocks but they are mostly concealed. In the stone walls are 

 numerous pieces of rather flat, thin bedded sandstone containing fossils 

 which evidently came from the adjacent fields. Some of the rocks are not 

 fossiliferous and others only contain layers of Crinoid segments. These 

 rocks are about west of the locality which has just been described to the 

 northeast of Deer Park. Farther north on the road from Deer Park sta- 

 tion loose pieces of sandstone which contain large numbers of DouvUlina 

 cayuta Hall and some specimens of Canmrotoechia occur by the side of the 

 highway and in the field. In Garrett County DouvUlina cayuta Hall and 

 Leptostrophia perplana (Conrad), var. nervosa Hall are, apparently, the 

 first abundant species in the Chemung fauna. On the road to the south 

 was a little red shale which, probably, occurs below the fossiliferous 

 layers. 



From the collections made in the vicinity of Deer Park, mainly from 

 the exposure by the roadside just northeast of the village and from the 

 side of the road running north from Deer Park station and the adjacent 

 fields. Dr. J. M. Clarke has identified the following fauna, which is one 

 of the most extensive found in the Chemung rocks of Maryland: Arnbo- 

 coelia umbonata (Conrad), Chonetes sdtulus Hall, DouvUlina arcuata 



