MARKINGS IN PENNSYLVANIAN SANDSTONES 7a 
upper corner, Fig. 4). Cross-markings are infrequent in the 
well-striated surfaces, but common in the more irregular markings 
described below (Figs. 3, 6, 7). Professor Hall, however, figured 
one well-striated slab with three sets of parallel furrows." 
Fic. 4.—A slab of sandstone and a plaster cast of the same showing the original 
strand surface in the cast. The markings were depressions in the strands. Some of 
them represent very small dents made by objects swept along, but two of them strongly 
suggest nodal impressions of plants which, it is believed, lay on the strand. Locality, 
Naples, New York; Portage group of the Upper Devonian. Specimen in the New 
York State Museum. 
Fossils are occasionally found in the grooves, but small rod- 
like impressions and gouges in the strand, as seen in Figure 4, 
are more common. Drifted shells fill grooves in the Beekmantown 
of Valcour Island, Lake Champlain, according to Dr. Ruedemann. 
Hall figures a slab showing on the original strand surface, two 
t Reproduced by Clarke, op. cit., p. 202. 
