Some Recent Graptolitic Literature. — Gurley. 35 
Second sandstone. 
Third Magnesian limestone. 
Third sandstone. 
Fourth Magnesian limestone. 
The term Magnesian has been applied to rocks of other ages, 
and, for that reason, has not been well taken. The term Ozark, is 
peculiarh' well adapted, for it includes rocks that are not only 
lound amid the Ozarks, but are there better developed. 
In south-eastern Missouri certain members of the lower part of 
the series are wanting, and the Third Magnesian limestone is not 
well separated from a lower limestone which may be the equiva- 
lent of the Fourth. The lowest rock near Mine La Motte is a 
sandstone which, near Fredericktown rests directly upon granite. 
There are also occasional exposures of a variegated red, purple, 
buflf and drab marble whose position is above the sandstone. 
Above the marble beds are gritstones and magnesian limestones 
and dolomites which are the lead-bearing rocks of Madison and St. 
Frangois counties. These lower limestones contain LinguJeUa 
lamhorni of Meek at several places. If that fossil is of Potsdam 
age, then these lower limestones and sandstones are of Potsdam 
age. The marble beds have occasionally furnished beautiful 
polished slabs of marble. Nearh' 35 years ago Mr. Henry Cobb, of 
St. Louis, had a quany of it opened near Ironton, in Iron county, 
and attempted to bring it into notice. He termed it "Ozark"' 
marble, and in deference to him I will still use the name. The 
series in Iron, Madison, and St. Francois counties is as follows: 
Ozark Series. 
Second sandstone — on hill-tops with chert 125 feet 
Third Magnesian limestone with chert and quartz. . . 225 " 
Gritstone and Lingula beds 50 " 
Ozark Marble beds 25 " 
Lower sandstone and conglomerate 90 " 
The above series rests on Archaean porphjTies and granite. 
University Columlna, Mo., April, 1891. 
SOME RECENT GRAPTOLITIC LITERATURE. 
By R. R. Gurley, U. S. National Museum. 
Besides several minor papers* the graptolitic literature of 1S90 com- 
*De Roiiville, Prof. P. G. Note .sur le presence du Pleurodictynmnrohlematif^um 
dans le Devonien de Cabrieres et sur un nouvel liorizon de Graptolites daus 
le Silurif'ii de Cabrieres : Bull. Geol. See. France, XVIII. pp. 19G-97 (Notes dis- 
covery of an Arenig fauna). 
Dodge, W. W. Some Silurian Graptolites from Northern Maine; Am. Jour. Sci., 
XL, pp. 153-55 (Notes occurence of the Norman's Kill fauna in Penobscot 
County). 
Nicbol.son, H. Olipbant. Notes on the discovery of Tri'/onoaraptvs enstifurmi!^. 
Hall (sp.) and of a variety of JJidiimoyraptns V-frortus Salter in the SKiddaw 
slates; Geol. Mag. VII, pp. 340-44 (Describes //. V-fractus var. volucer, var. 
