22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 68 



Following the geologic work in the Appalachian \'alley in the 

 early summer. Dr. Bassler proceeded to central Kentucky where 

 he spent several weeks in explorations for suitable exhibition speci- 

 mens covering the general subject of stratigraphic paleontologv. It 

 was especially desirable that such phenomena as stratification, the 

 occurrence of fossils, and unconformities should ])e illustrated in 

 the Museum, and esi)ecial efforts were made to secure specimens 

 exhibiting these features. Much discrimination was necessary in the 

 selection of these objects, as it was essential to (jljtain s])eciniens of 

 such size as to be a])preciated bv the ])ublic and still not too large for 



Fig. 21. — Surface of limestone layer A, of fig. 20, one-sixth natural size, 

 showing " edgewise " conglomerate. Photograph jjy Bassler. 



the available space, wliich is somewhat limited. This difficulty com- 

 plicated the work, but the selection finally made was extremely satis- 

 factory. 



The early Paleozoic coral reef near Louisville, Kentuckv, from 

 which a section six by ten feet in dimensions had been quarried and 

 placed on exhibition during the summer of 1916, was revisited and 

 several additional layers of highly fossiliferous shale and limestone 

 w^ere secured. These have now been added in their proper position 

 to the coral reef mount so that this single exhibit now illustrates the 

 subjects of stratification in general, horizontal strata, change of 

 lithologv from limestone to shale, tlie occurrence of fossils in these 



