Microscopic chondrichthyan remains from Pennsylvanian marine rocks of Ohio and adjacent areas /

Abstract

This reproduction was made from a copy of a m anuscript sent to us for publication and microfilming.While the m ost advanced technology has been used to pho tograph and reproduce this m anuscript, the quality of the reproduction Is heavily dependent upon the quality of the material submitted.Pages In any m anuscript may have Indistinct print.In all cases the best available copy has been filmed.The following explanation of techniques Is provided to help clarify notations which may appear on this reproduction.1.