BULL. GEOL. SOC. AM. 



VOL. 18, 1906, PL. 51 



Fig. 1. — n.-iXT IJIPEESSION in upper Mauch Chunk Shales^ White Haven^ Pennsylvania 

 Impression emphasized by India inli wasli applied to photograph 



■ I 



Figure 2. — Plant Impression from Madch Chunk Pormation, Pottsville, near Locality Shown in Plate .50 



PLANT IMPRESSIONS IN MAUCH CHUNK SHALES ii 



