312 Notices of Memoir s—iJI. R. Zeiller— Coal Flora Bp ids. 
4, That this process of decay has furnished the material, not only 
for the clays, sands, and iron-oxides from the beginning of Paleozoic 
time to the present, but also for the corresponding rocks of Hozoic 
time, which have been formed from the older rocks by the more or 
less complete loss of protoxide bases. The bases thus separated 
from crystalline silicated rocks have been the source, directly or 
indirectly, of all limestones and carbonated rocks, and have, more- 
over, caused profound secular changes in the composition of the 
ocean’s waters. The decomposition of sulphuretted ores in the 
Eozoic rocks has given rise to oxidized iron-ores in situ, and to rich 
copper-deposits in various geological periods. 
5. That the rounded masses of crystalline rocks, left in the pro- 
cess of decay, constitute not only the boulders of the drift, but, 
judging from analogy, the similar masses in conglomerates of various 
ages, going back to Hozoic times; and that not only the forms of 
such detached masses, but the surface-outlines of eroded regions of 
crystalline rocks, were determined by the preceding process of sub- 
aerial decay of these rocks. 
IJ.—Nores sug tA Frore Houiwirre pes Asturies. Par M. R. 
ZeitterR. Mémoires de la Société Geologique du Nord. ‘Tome 
Premier. Lille, 1882. 
YHIS memoir comprises a critical examination by M. R. Zeiller of — 
about fifty species of fossil plants, chiefly Ferns and Sigillaria, 
collected by Dr. C. Barrois from the Coal-measures of Asturias. 
M. Zeiller has compared all the specimens with similar or allied 
forms from the Coal-measures of France, England, and America, 
and has identified all of them with previously known forms. 
The Coal-measures of Asturias are referred to three basins, the 
central, northern and western, but the plants occur at different 
horizons. 
According to M. Zeiller, the plants received from Dr. C. Barrois 
indicate two great stages in the Coal-formation of the Asturias, and 
in this respect he is corroborated by M. Grand’ Eury, who has also 
seen the specimens. The upper stage is represented at Tineo, Lomes, 
Arnao, and Ferrojies, the deposits of Tineo and Lomes belong to the 
sub-superior, at least those of Tineo to the upper part; those of 
Arnao and Ferrones occupy a position perhaps a little higher, that 
is to say, at the top of the series. The middle coal division is 
represented throughout the central basin and at Santo-Firme, the 
beds at Mieres, Sama, Ciano, ete. (central basin) belong to the upper 
part of the middle stage, and those of Santo-Firme to the middle, 
if not to the lower middle stage. The lower coal division is seen in 
the Cordal de Lena to the west of Pola de Leia. As to the small 
basins of Quiros and Onis, the specimens did not permit the age to 
be fixed, from their small numbers and the absence of any charac- 
teristic species. This memoir was intended to form part of the 
‘Recherches sur les Terrains Anciens des Asturies,” etc. (see Preface, 
p- 7), in which work, pp. 551-570, Dr. Barrois has fully described the 
characters and position of the Coal-fields of Asturias. J. M. 
