H. 8. Williams—Fauna of the Chemung Group. 101 
beds, and is so closely related to O. Calvani of the Iowa beds 
fauna, as it appears at Chemung Narrows, N. Y., ; 
come in to the deposits of this meridian until after the deposi- 
hon of six hundred feet of coarse sandy shales. The High- 
of the Chemung group. 
Its more common species are: 
Strophodonta mucronata, Rhynchonella eximia, 
Spirifer mesocostalis, Cryptonella eudora, 
Spirifer mesostrialis, Orthis impressa. 
Productella speciosa, 
