REPORT OF THE DIRECTOR I919 IO9 



from the entire shale section. He found two exposures of shale, one 

 extending from Arnolds bay northward (and southward) until 

 rather abruptly replaced by the heavy Trenton limestone, apparently 

 by a fault. This limestone farther north changes gradually through 

 about 50 to 100 feet of transition beds (limestone beds, about 2 feet 

 thick with soft' black shale between) into the black shale. 



Mr. Gould and the writer visited the section in 1919, collecting 

 from the top of the Trenton limestone, the transition beds and all 

 parts of the overlying black shale; the latter, taking the covered 

 intervals at the north end in account, reaches 400 feet or more in 

 thickness. 



The top of the Trenton limestone, just below the transition beds 

 consists of gray crystalline limestone and contains : 



Mesotrypa quebecensis Ami 

 Rafinesquina sp. 



Plectambonites sericeus (Sowerby) 

 Dalmanella rogata (Sardeson) 

 Parastrophia hemiplicata (Hall) 

 Protozyga exigua (Hall) 

 Calymmene senaria Conrad 

 Isotelus sp. (fragments) 

 Ceraurus pleurexanthemus Green 

 Aparchites minutissimus (Hall) 

 Leperditia sp. 



On top of the limestone cliff, the writer had before collected: 



Streptelasma corniculum (Hall) 

 Dalmanella cf. rogata (Sardeson) 

 Liospira americana (Billings) 

 Spyroceras bilineatum (Hall) 

 Bythocypris cylindrica (Hall) 

 Primitia sp. 



The limestone at the beginning of the transition series has afforded : 



Mesotrypa quebecensis Ami 

 Plectambonites sericeus (Sowerby) 

 Dinorthis meedsi W. & S. (Large form) c 



The intercalated shale contains near the base: 



Climacograptus strictus Ruedemann (putillus auct.) 

 Climacograptus spiniferus Ruedemann r (bicornis auct.) 

 Mesotrypa quebecensis Ami 

 Dalmanella rogata Sardeson c 

 Rafinesquina sp. 



