Geology and Mineralogy. 149 
ich were not perceptible at ordinary pressures, together with 
the always present sodium lines an um line which ap- 
clusions of Cazin that the continuous spectrum 1s 
: c 
IL GroLtoagy AND MINERALOGY. 
1. Silurian Plants ; by Leo Lesquereux. 12 pp. 8vo. From 
the Proceedings of the Amer. Phil. Soc., Oct, 19, 1877.—Mr. Les- 
quereux has here published, with a plate for illustration, his latest 
cinnati group, first brought out in 1876, gives additional maport. 
ance and interest to the earlier discoveries 1n Ohio. M . Lesqu 
reux calls the species he first described Protostigma sigillaroides : 
nd adds now, from the same rocks—the Cincinnati group, near 
Cincinnati, Sphenophyllnm primevum Lesqx., Psilophytum gra- 
cillimum Lesqx. (near Covington, Ky., opposite Cincinnati). : 
In thi er Mr. Lesquereux also describes a Fungus (Bhi 
zomorpha sigillarice Lesqx.), found in connection with a Sigilla- 
ria in cannel coal at Cannelton, Beaver Co., Kentucky. 
: ; 2 by WarrEN Upuam. 
