Explanations ok Platks. 



239 



PkiSiMODictya aulopiiia, sp. nov. 



Page 88. 

 (See Plates XXXIV and XLI.) 



Figure 7. The basal portion of a weathered specimen ; showing the concave 



prism-faces. 

 Figure 8. A fragment of the median portion of a specimen ; showing the 



concave prism-faces and the extremely fine surface reticulation. 



Chemung group. Wellsville, New York. 



