The upper Devonian and lower Mississippian of southwestern Pennsylvania /
Laird, Wilson Morrow, 1915-
The upper Devonian and lower Mississippian of southwestern Pennsylvania / by Wilson M. Laird. - [Harrisburg : 1941] - 1 p. l., 23 p. : tables, diagrs. ; 23 cm.
At head of title: ... Commonwealth of Pennsylvania. Dept. of internal affairs ... Topographic and geologic survey ...
"Literature survey": p. 2-4.
gs 41000156
Geology--Pennsylvania.
Geology, Stratigraphic--Devonian.
Geology, Stratigraphic--Mississippian.
QE157 / .A293 no. 126
The upper Devonian and lower Mississippian of southwestern Pennsylvania / by Wilson M. Laird. - [Harrisburg : 1941] - 1 p. l., 23 p. : tables, diagrs. ; 23 cm.
At head of title: ... Commonwealth of Pennsylvania. Dept. of internal affairs ... Topographic and geologic survey ...
"Literature survey": p. 2-4.
gs 41000156
Geology--Pennsylvania.
Geology, Stratigraphic--Devonian.
Geology, Stratigraphic--Mississippian.
QE157 / .A293 no. 126