“4 
L. Lesquereux on the Coal Formations of N. America, 377 
any bed of coal of sufficient thickness to encourage the working. 
Thus the shales are still unopened and no chance is given of 
examining them. In Kentucky where in the same space the 
coal is more developed and has been opened at different places 
and different geological horizons, the shales roofing the coal- 
strata are mostly very bituminous and contain especially ani- 
mal remains, fishes and shells, either with or without few fos- 
sil plants. Nevertheless I have been able to find here and 
there some determinable species affording points of comparison 
for the distribution of the coal-plants in those higher measures. 
Thus, the fire-clay of the bottoms of all the coal-strata is always 
filled with remains (leaves only) of Stgmaria ficoides Brgt., and 
at any place where the coal is formed, it shows on its horizontal 
sections the carbonized prints of Calamites, Pecopteris and Stg- 
maria. 
Coal No. 6 is covered by a schistose, gray, laminated sand- 
a blackened by broken fragments of ferns. ree of 
ec 
peey of well-preserved fossil shells, of scales and teeth of 
shes, and of remains of ferns evidently floated. ‘Two species 
there are at Pittsburg well preserve 
Re Bret., WV. flexuosa Bregt., 
arborescens Bret., P. cyathea . rh 
Bret., three species of Galamsies and one Sigillaria. The same 
Species with a far greater proportion 0 
AM. JOUR. SCL—SECOND SERIES, Vou. XXX, No. 90.—NOV., 1860. 
43 
