ITO The Lower Devonian Deposits of Maryland 



Vertical Total 

 thickness vertical 

 feet thickness 

 menoides and bryozoa, 1.6; Fenestella idalia, Dalmanites pleu- 

 roptyx (a), Leptwna rhomboidalis (a), Actinopteria communis 

 (a), Chonostrophia helderbergiw (aa), Rhipidomella oblata, 

 Schuchertella woolworthana, and Strophonella leavenivorthana, 

 1.1 2.5 2.5 



Thickness of New Scotland member exposed 29.3 



Coeymans Member 

 Thin bed of gray crystalline limestone with a chert layer. .. . 0.7 13.() 



Shale parting 0.1 12.9 



Heavy bed of crinoidal limestone with a chert layer near 

 middle and at base. At base of unit occur Leptwnisca concava, 

 Actinopteria communis, Tcniaculites elongatus, Gypidula coey- 

 manensis (a), Rhipidomella sp., Stropheodonta arata, Stropho- 

 nella leavenworthana. Strophonella punctulifera, 1.9; Gypidula 



coeymanensis, Leptwna rhomboidalis, 2.4 3.0 12.8 



Massive bed of gray crystalline limestone. Between 2.6 and 

 3 feet below the base of the unit are a number of bands of 

 sand which weather out as brown ridges on the surface. At the 

 base of the unit are rounded limestone fragments, about 2 to 4 

 inches in thickness. The line of contact with the Keyser is 

 rather sinuous. 6.8 feet above the base is a Stromatopora bed. 

 Dalmanites pleuroptyx, Gypidula coeymanensis, Atrypa reticu- 

 laris, Schuchertella woolworthana, Leptcena rhomboidalis and 

 Stropheodonta arata occur in abundance throughout; corals, 

 Spirifer cyclopterus, Rhipidomella oblata, Strophonella leaven- 

 worthana, Strophonella punctulifera occur at top of unit; chae- 

 tetoid bryozoa Stropheodonta planulata, crinoid rings, Vnci- 

 nulus sp., 8.3; Spirifer cyclopterus, 3.0 feet; Stromatoporoid sp., 

 Favosites helderbergiw, Fenestelloid bryozoa Uncinulus sp., 

 2.6 9.8 9.8 



Thickness of Coeymans member 13.6 



Keyser Member 

 For description see pages 137-138. 



IV. Section at Riverside Station ' 

 One of the most conspicuous cliffs along the Potomac Eiver is in Knobly 

 Mountain, West Virginia, east of Potomac Station. It is something over 



* The section was described by R. B. Rowe who does not give precise measure- 

 ments. 



