Raymond: Sections in the Conemaugh Series. 169 



2 1. The Pine Creek limestone is apt to be very full of sand and 

 clay, and is particularly so in these sections east of Pittsburgh. In the 

 cut east of Donohoe its horizon was found only after a most careful 

 search, and then could be identified only by its fossils, which are not 

 common at that locality. A similar condition is seen at Trafford 

 (formerly Stewart Station), and the other cuttings between that station 

 and Ardara. 



20, 19, 18. The Buffalo sandstone is here much thicker than usual. 

 I'he lower part is massive and in places conglomeritic, while the upper 

 part is soft and tends to become shaly. The base is irregular and the 

 thickness variable. 



16. The Brush Creek shales and limestone are full of very well 

 preserved fossils, largely pelecypods and gastropods, and as a large 

 amount of this material has been taken out and scattered along the 

 dumps on either side of the cut, this is an excellent collecting ground. 

 I am indebted to Father Wirtner, O.S.B., of Penn Station, for having 

 called my attention to this locality. 



The following are the more common species: 



Eiiomphaius catilloides Conrad, 



Bulimorpha nitidida (Meek and Worthen), 



Sphcerodotfia primaginia ( Conrad ) , 



Worthenia tabulata (Hall), 



Trepospira illinoisensis (Worthen), 



Bellerophoii percarinati/s Conrad, 



Euphemus cai'bonarius (Cox), 



Patellostium montfortianum (Norwood and Pratten), 



A star tell a vera Hall, 



Marginifcra wabashensis (Norwood and Pratten). 



This is probably No. 19 of Dr. Stevenson's section (his fig. 32), 

 while his No. 22 would be the Mason coal. • 



7. The concealed interval is not readily estimated, but there are 

 probably not much more than 15 feet ot" strata missing. This figure 

 was obtained by taking the dip of the top of the Upper Freeport and 

 the top of the Mason coal. The top of the Upper Freeport is rather 

 irregular (is, in fact, faulted in one place), and the best measure- 

 ments to be obtained gave the apparent dip as i foot in 29, while the 

 dip of the Mason coal is i foot in 16. As the course of the 

 railroad is here approximately perpendicular to the strike, this is 

 nearly the true dip. As calculated with these data, the maximum 



