NEW YORK STATE MUSEUM 



PORT EWEN FAUNA 



Corals 



S Enterolasma strictum ( Hall) x 



G Cladopora </. styphdia Clarke 



CV Duncanella rudis Girty x 



V Favosites helderbergiae Hall x 



CV Pleurodictyum lenticularc ( Hall) x 



CV Zaphrentis roemeri Hall x 



Sponges 



CV Hindia fibrosa Roemer ■ x 



58 13 



a 



26 



Not only is the continued predominance of Helderberg species in this 

 summary, combined with the first appearance of Oriskany types, confirma- 

 tory of Professor Chadwick's view that the fauna is the passing phase of 

 the Helderberg but it is in accord with our views of affiliation in the case 

 of such clearly mixed combinations to assert that the presence of the later 

 species indicating a new invasion is a proper index of Oriskany age. 



Oriskany fauna. Considering now the composition of the more normal 

 Oriskany fauna in this eastern region in the light of newer developments 

 we are presented with the fact that there is yet no intimate distinction in 

 the species from the calcareous beds and those which are distinctively arena- 

 ceous. The limestones of this horizon are all pretty highly impregnated 

 with sand and their weathered parts always afford the best material for 

 study either in the form of silica replacements or sharp external and. internal 

 casts in residual sand. The fauna at Becraft mountain reported by Clarke 

 was obtained wholly from weathered residua of sandy limestone. The very 

 fine material obtained at and about Glenerie occurs best as silica replace- 

 ments, often of very remarkable perfection, in pockets filled with the loose 

 sand of rotted limestone, in all respects a parallel occurrence to the fine 



