272 Wasmuih on the Pittsburg Coal (Bed. 
The upper third. Two of the most constant fossils which 
attain their best development in this division are Rhyiichonella 
7ieglccta and StreptorhyncJuts sitbplauuDi. Ptcrhiea einacerata 
is the principal lamellibranch. Among the trilobites Dahna- 
7iites and Ho7ualonotiis are the prevailing forms, others being- 
seldom found. Corals are scarce, being jDrincipally an occasional 
Favosites. Cephalopods are almost entirely wanting, Ortho- 
ceras anitnlatnm being the only one noticed. Platystoina niag- 
arense is the only noteworthy gasteropod. Crinoidea are 
excessively rare, a few Caryocrnn\ a Callocystltes jeivetti and 
a type each of JMarlacriims warren! and I)e?idrocri/ms celsus 
being all that have been secured to date. 
It will be observed that most of the recorded species are in 
the loiver third', this is not alone due to the profusion of fossils 
there, but also to the more limited facilities for observation 
which have occurred in the rest of the shale, and the immense 
amount of material which must be worked over in order to get 
a few data. 
NOTES ON THE PITTSBURG COAL BED AND ITS 
DISTURBANCES. 
BY HENRY A. WASMUTII, M. E. 
The Westmoreland Coal Co. has opened the Pittsburg coal 
bed by a shaft at station "Biddle" on the Pennsylvania Rail- 
road. The shaft has struck the coal bed at about 190 feet deep 
on the northern flank or flexure of a basin, the synclinal axis of 
which has not been developed thus far. The area of the north- 
ern flank, controlled by the company referred to, has been 
opened on the English arid German systems of mining by divid- 
ing both extensions of the coal bed on the strike as well as on 
the incline into suitable pannels or divisions. Each pannel on 
the strike has three main entries, one for the empty mine 
wagons, one for the loaded wagons and the third one for the 
returnmg air (A B C, fig. i). From these main entries are 
urned off the butt entries D D D D (double entry system), thus 
