UPPER PALEOZOIC (CARBONIC). 253 
Virginia XI. — Greenbrier Group. 
Tennessee. ) f Mountain Limestone. 
Alabama. J 1 Siliceous Group. 
Indiana. — Mountain Limestone. 
Michigan. "] 
Illinois. I , 
Chester Group. 
St. Louis Group. 
Keokuk Group. 
Iowa. 
Missouri, j 
Nova Scotia. ~) 
New Brunswick. [■ Windsor Series. 
Newfoundland, j 
POCONO. 
Synonyms and Local Subdivisions. 
!Shenango Group. 
Meadville Group. 
Oil Creek Group in part. 
Virginia X. — New Kiver Series. 
r Cuyahoga Shale. 
I Berea Shale and Grit. 
Ohio: Waverly Group in part, j Bedford Shale. 
I Cleveland Shale. 
T6nnGSS66. 1 
. I , \ Absent or represented by the lowest beds of the Siliceous Group. 
Indiana. — Knobstone Group in part. 
Illinois. \ f Burlington Group. 
Iowa. / (■ Kinderhook Group. 
-,. , . f Michigan Salt Group. 
ic ugan. I Marshall Group. 
New York. — Upper part of the Catskill Gray Sandstones. 
Nova Scotia. — Horton Series. 
Eastern Quebec. — Bonaventure Series. 
No geographical term can be found which will designate the 
divisions properly, for which reason it might be well to retain the 
meaningless terms Umbral and Vespertine, applied to them many 
years ago by Professor Rogers ; as, however, most geologists 
prefer geographical names, Greenbrier and Pocono will have to 
be accepted as most nearly meeting the requirements. These are 
admirable divisions for the Appalachian, and their subdivisions 
in the Interior Basin can be made out without any difficulty. 
The contrast between tlie Appalachian area and the Interior 
Basin is very marked in rocks of the Lower Carbonic. Tiie Green- 
brier beds are persistent throughout the former area. Within 
most of Pennsylvania and Ohio, and along the southeast border 
of the area, the deposit is of shale and sandstone; while in West 
