MARYLAND GEOLOGICAL SURVEY 167 



acteristic fossil is the pod-shaped crustacean Caryocaris silicula, indi- 

 viduals of which are often quite common in the shaly limestones. 



The Corynoides bed has been recognized in the Appalachian Valley 

 from Pennsylvania south to Virginia. In Maryland the shale outcrops 

 in the vicinity of Williamsport and Pinesburg Station have furnished the 

 few fossils so far discovered in this bed. 



Fauna of the Corynoides Bed 



Climacograptus putillus (Hall) 



Climacograptus spinifer (Ruedemann) 



Corynoides calicularis Nicholson 



Leptobolus inslgnis Hall 



Schizocrania filosa (Hall) 



Cyclora minuta Hall 



CryptolitJius tesselatus Green 



Triarthrus becki Green 



Lepidocoleus jamesi (Hall and Whitfield) 



Caryocaris silicula n. sp. 



Fossils of the Eden Division, Martinsburg Shale. The splendid ex- 

 posures of the lower Cincinnatian shales, later designated the Eden shale, 

 in the vicinity of Cincinnati, Ohio, have afforded a wealth of excellently 

 preserved fossils which have been so widely studied by paleontologists that 

 a large described fauna has resulted. The occurrence of this same fauna, 

 well enough preserved for the accurate recognition of at least 42 species, 

 in the sandy upper portion of the Martinsburg shale of Pennsylvania, 

 Maryland, and Virginia, is one of the interesting discoveries of recent 

 years in Appalachian geology. 



Numerous exposures of this sandy upper portion of the Martinsburg 

 shale occur along the Western Maryland Eailway between Williamsport 

 and Pinesburg Station, but the conditions of sedimentation in this part 

 of the valley seem to have been unfavorable for life, as no fossils could be 

 found. The northward and southward extensions of this Martinsburg 

 shale belt likewise have furnished no fossils, but the shale exposures in 

 the mountains to the west exhibit several fossiliferous zones. In Mary- 

 land it happens that no good exposures of the upper Martinsburg occur 



