ILLUSTRATIONS 17 



PLATE FACING PAGE 



XVII. Fig. 1. An average example of the cauliflower chert from the 

 base of the Stones River limestone. Vicinity of Bostetter, 

 Maryland 120 



Fig. 2. Typical natural outcrop of upper Stones River limestone 

 in cleared fields, one-half mile west of Pinesburg, Maryland. 

 The growth of cedar trees on this pure limestone is illustrated. 120 

 XVIII. Fig. 1. View of edgewise conglomerate in Stones River forma- 

 tion, two and one-half miles southeast of Williamsport, Mary- 

 land 122 



Fig. 1. View of quarry in Chambersburg limestone at Pinesburg 



Station, Maryland 122 



XIX. Fig. 1. Photograph showing succession of sinks along the band 

 of outcrop of the Stones River limestone, one-half mile south 

 of Wilson, Maryland. The road to the east follows the Cham- 

 bersburg limestone 126 



Fig. 2. Near view of a sink filled with water 126 



XX. Fig. 1. Typical exposure of the Echinospherites bed of the Cham- 

 bersburg limestone showing characteristic cobbly effect. Rail- 

 road cut at Pinesburg Station, Maryland 130 



Fig. 2. Typical outcrop of steeply dipping Chambersburg lime- 

 stone along road between Pinesburg and Pinesburg Station, 



Maryland 130 



XXI. Fig. 1. View in the Tabler quarry just south of Frederick, Mary- 

 land, showing contact of the massive Beekmantown limestone 

 overlaid by the thin-bedded Frederick limestone with a dis- 

 tinct line of unconformity separating them 160 



Fig. 2. Fold in sandy upper (Eden) portion of Martinsburg 

 shale along Western Maryland Railway, three-fourths mile 



west of Williamsport, Maryland 160 



XXII. Fig. 1. Exposure of lower part of Martinsburg shale along 

 Western Maryland Railway, about one-half mile east of Pines- 

 burg Station, Maryland. The gentle dip of the strata and the 

 cleavage at right angles are well shown 104 



Fig. 2. View across valley of Conococheague and Beekmantown 

 limestones, from a point two miles east of Little Georgetown, 

 West Virginia. Conococheague chert strews the foreground. 

 North Mountain in the distance contains the Juniata and 



Tuscarora formations 164 



XXIII. Fig. 1. View of Martinsburg shale topography, looking northeast 

 from a point one-half mile south of Wilson, Maryland. Cono- 

 cocheague Creek is seen in the foreground and the National 

 Highway in the middle 170 



Fig. 2. Valley of Martinsburg shale (Blair Valley, Maryland) 

 viewed from road, just west of Union Bethel Church. The 

 mountains on both sides are formed of the Juniata and Tus- 

 carora formations 170 



XXIV to LVI1I. Systematic Paleontology 374-408 



