GEOLOGICAL SOCIETY OF PENNSYLVANIA. 



199 



4th. P). 8, fig. 1. Sketch looking to the south west, 

 of the north side of the valley, showing a corresponding 

 shelf or line of beach on the south or inner slope of Path 

 mountain. 



5th. PL 8, fig. 2. View of the north side looking 

 towards the north east, exhibiting the knobs or parallel 

 ridges, and the line of beach ranging along Path moun- 

 tain. 



6th. PL 8, fig. 4. View of the gorge of the Kisha- 

 coquillas creek, through Jack's mountain, looking south, 

 from the subordinate hills of central limestone. 



These outline views were all taken with the camera 

 lucida, at the time of a deep snow, and the perspective 

 is therefore correctly exhibited. 



In the map we have included a few geological memo- 

 randa southward of Kishacoquillas valley, to explain its 

 position with reference to the beds of Fucoides, described 

 by the writer in your Transactions,* and also of an inter- 

 esting deposit of fossil shells, which will probably be the 

 subject of a future communication. This extension is 

 also useful in showing the direction taken by the waters 

 discharged from the lake, indicated by the assemblage 

 of detritus on the low lands between the gorge and the 

 Juniata. With regard to the section pi. 9, fig. 2, it 

 will be seen that all the beds comprised within its limits 

 incline one way, pointing to the south, their direction or 

 courses running parallel with the ridges. These ridges 

 consist of a numerous series of white, yellow and red 

 sandstones, and of red conglomerates. The northern half 

 of Jack's mountain is red sandstone and red conglome- 

 rate, while its southern slope comprises the white sand- 

 stones. The division line between these two formations 

 or deposits runs exactly along the crest of the ridge ; 

 the prevailing dip being 50 to 60° degrees south. 



* Ante, page 5. 



