58 The Middle Devonian Deposits of Maryland 



The next 100 feet of the fissile hhick sliale^;, !) of the section, appears 

 to be barren except for some tliin bands of l)hie limestone which are 

 crowded with the minute shells of a variety of Ambocoelia virginiana. 



The lowest Hamilton fauna observed appears in some hard sandj' beds 

 about 250 yards east of the end of the cut. 



Exposure at 'Tuiioloii-dij. — At Tonoloway, opposite Great Cacapon, W. 

 Va., nearly the whole of the Devonian below the Parkhead member of the 

 Jennings is exposed with the exception of the Marcellus shale which is 

 almost entirely concealed in the bottom of a small valley which reaches the 

 Potomac along the strike of the lieds of this portion of the section. At the 

 base of the Marcellus shale and immediately above the Oriskany sandstone 

 about 60 feet of interbedded greenish-drab and black blocky shale is 

 exposed representing the Onondaga shale. The following fauna was 

 found in these beds : 



Strophalosia truncata r 



Rhipidomella vantixenii c 



Ambocoelia iivihonata c 



Nucleospira concinna c 



Dalmanella lenticularis c 



Anoplia cf. nuclenta r 



Leptaenisca australis r 



Styliolina fissureUa a 



Phacops cristata r 



Bollia ungula c 



Bollia ohesa r 



Craterillina sp. 



Poh/gnathus sp. undet r 



Four hundred feet or more above this fauna the typical Hamilton 

 fauna appears in this section. 



Exposure at IlancocJi-. — At Hancock the Onondaga fauna was found on 

 the hill northwest of town, just east of the old sand quarr}', in green blocky 

 clay shale. About GO feet above the Oriskany sandstone at this locality 

 the following fossils were secured : 



Ambocoelia umbonata r 



Styliolina fissitrclln a 



Phacops sp. undet. 



