120 The Lower Devonian Deposits of Maryland 



of so large a number of species known elsewhere only in older strata, and 

 by the abrupt lithological and faunal break and probable unconformity 

 which separates the Keyser member from the overlying Coeymans of Mary- 

 land. Three species of this zone, Spirlfer vantLxemi var. prognosticus, 

 Tentaculites gyracanthus, and Leperditia alioides suggest a relationship 

 to the Manlius. 



The fauna of the Keyser member, considered as a whole, shows pro- 

 nounced relations to the Helderberg to which it is referred. 



Coeymans Member 

 The guide fossil of the Coeymans is Gypidula coeymanensis, which 

 occurs eveiywhere in this member in Maryland as in New York. The 

 following table clearly shows its Coeymans age : 



Number Per cent 



Species occurring elsewhere 19 87 



Species restricted to Maryland 3 13 



Total 22 



Occurring in the Coeymans of New York and New Jersey 18 82 



It also resembles the Coeymans of New York in its lithology being a 

 massive ciystalline limestone carrying many crinoid and Lepadocystis 

 stems. 



New Scotland Member 



The New Scotland member is characterized by the presence of Spirifer 

 macropleurus which is found at all the outcrops of the cherty limestone. 

 Among the other abundant species are Spirifer perlamellosiis, Scliu- 

 chertella woolworthana, Stroplionella leavenworthana, Dalmanella pere- 

 Icgans, MeristeUa arcuaia and species of the genera Trematospira and 

 Eatonia. The similarity of the fauna of this member to that of the New 

 Scotland of New York is clearly shown in the following table: 



Number Per cent 



Species occurring elsewhere 73 91 



Species restricted to Maryland 7 9 



Total 80 



Species occurring in the New Scotland of New York and New 

 Jersey 68 85 



