386 The Amoican Geologist. June, i899 
Diplapora and Lyellia. Heliolitichu are most common in Upper Silur- 
ian strata; certain genera are found in the Lower Silurian; one specie? 
is exclusively Devonian. 
Besides the species already named by Eichwald, '^IcCoy, Rocmer, 
Ltc. there are twenty-five new species described in this memoir. 
The memoir is accompanied by twelve beautifully executed plates, 
with numerous figures, showing by sections and etched surfaces the 
structure of the several species described; and it is very thorough, and 
exhaustive of the subject considered. o. k. m. 
Des relations des Mers Devonicnncs de Bretagne ct des Ardennes, 
par Chas. Barrois. (Society geologique du Nord, Annales, T. xxvi, p. 
260, 1898.) 
Dr. Barrois' extensive knowledge of the Devonian rocks 
of France enables him to write with much confidence on the 
physical conditions of that country during the Devonian age. 
The conclusions in this article are based largely on the 
pakeontology. He says there were three great sedimentary areas, 
dififering altogether in their relief and their bathymetric conditions. 
These areas diflfer entirely in proceeding from north to south, but on 
the contrary present great uniformity of conditions when followed from 
east to west, and true homozoic provinces may be recognized in 
proceeding in that direction. 
The first province includes the north of Great Britain and Scandi- 
navia; this is the continental region with lacustrine and fiuviatile for- 
mations. The second extends from the south of England to the 
north of Germany. The third province of Paleozoic times, corre- 
sponds to a littoral zone; this registers the secular variations of the 
Devonian shores. The third province extends from west to east, 
from Britain to the Plarz; its sediments are thinner than those of the 
preceding province, they are finer and more pelagic by their lithological 
character and thin fauna; this province is characterized by its pelagic 
facies, mud "ooze" with pteropods holding calcareous nodules witham- 
monoid shells. With similar characters the Devonian extends into 
Spain and far to the east. The central plateaux of France, Spain, 
Bohemia, etc., were islands in this Devonian sea. 
L 'Extension du Silurien Snperieur dans le Pas-de-Calais par Chas. 
Barrois. Ibidem. T. xxvii, p. 212, (1898). 
In the exploitation of coal beds beneath the Cretaceous formation 
near Calais an Upper Silurian limestone was struck which contained 
fossils of the age of the Wenlock. This limestone has heretofore 
been assigned to the Lower Carboniferous, but the fossils prove it Si- 
lurian. The presence of a Silurian limestone here shows a great fault, 
as existant before the deposition of the chalk, by which the older 
rocks were brought to the surface in post-Carboniferous times. 
Les Goniatites du Ravin de Conlarie {Haute Garonne) par Cha.s. 
Barrois. Ibid. T. xxvii, p. 260, (i8q8). 
Goniatites of several genera were found in this ravine. From the 
