752 CONTENTS. 



Page. 



Upper limit of the Pottsville foniiatioii 823 



Flora of the base of the Lower Coal Measures in the Sduthern Anthracite 



field 823 



Flora in the roof shales of the Twin (Buck Mountain) coal 824 



The paleontologic uj)per limit of the formation 829 



Lower limit of the Pottsville formation 831 



The Pottsville formation in the Dauphin liasin 832 



Age of the coals in Lorberry Gap 833 



Section at Lorberry ( raji 833 



The fault in Sharp ^lonntain 835 



Section at Fishing Creek Gaj) 838 



Western limit of the fault 839 



Position of the formation al()ng Sharp Mountair. 841 



Section at Black Spring < 'ap 842 



Section at Gold 3Iine ( Jaj. 842 



Section at Ransch ( rd\\ Lebanon County . S44 



Yellow Springs Gap 845 



Rattling Run Gap 849 



Big Flats 850 



Short ^lountain shaftings west of Big Flats 851 



The Lykens coals in Stony Mountain 854 



Geiieral conditions relating to the occurrence of the Lykens coals in the 



Dauphin Basin 855 



Thickness of the formation in tlie Southern Anthracite field 857 



Variation in the constituent terranes in the formation 862 



Notes on or descriptions of some of tne more characteristic species of fossil 



plants of the Pottsville formation in the Southern Anthracite field 865 



List of fossil plants from the Pottsville formation in the Southern Antlira- 



cite field - 866 



Notes and descriptions 868 



Age of the Pottsville formation 911 



Summarv of conclusions . . 913 



