393 
Review of Recent Geological Literature. 
The name of each species is followed by the chemical formula accord¬ 
ing to the most recent research. After the expression of the crystalline 
system, which is followed by the dimensions of the primitive form, the 
author has added the values of the parameters referred to the usual 
axes, the forms observed from localities mentioned in the work, angles 
measured and calculated, peculiarities of elongation or flattening, 
twinning, striation, hemihedry and mechanical deformations. Under 
cleavage he has included also gliding-planes with the designation 
“ planes of separation,” which he considers, nevertheless, of secondary 
origin. Hardness, specific gravity, color, inclusions, pleochroism, 
chemical composition, blowpipe characters, alteration and its products 
are followed by a statement of the distinguishing characteristics of each 
species. In giving the geographical distribution of the various species 
in France the author follows a classification by means of which the 
geological relations and sometimes the origin of the species are expressed. 
It is, however, in the matter of .the optic properties of minerals that 
the work shows at once its unique character and its greatest excellence.. 
An expert microscopist could hardly produce a work of this kind with¬ 
out placing great stress on this branch of mineralogy, and this quality 
of the volume will render it a favorite with petrographers. The excel¬ 
lent methods of the French petrographers find in this work their con¬ 
stant application and test. It is a companion and supplement of “ Miner- 
aux des Roches,” by Michel-Levy and Lacroix. The author takes 
special pains to express the optic characters of microscopic crystals. In 
general, the optic properties are expressed by the use of little rectangu¬ 
lar diagrams which indicate the position of the plane of the optic axes, 
the size of the angle 2V, and frequently the apparent angle 2E about 
the acute bisectrix. 
The work is characterized, besides, by the publication for the first 
time of a great number of new observations, largely microscopic, on the 
properties of minerals. It marks, therefore, an important epoch in the 
progressive mineralogy of France, and constitutes a valuable contribu¬ 
tion to the science at large. Associated as the author is, intimately, 
w T ith the leading mineralogists and petrographers of France, Des 
Cloiseaux, Michel-Levy, and Fonque, he has had access not only to their 
material, but to all the collections in the various museums, public and 
private, of Paris, and of the provinces. While it is, therefore, in name, 
a description of the minerals of France, it amounts to a full treatment 
of nearly all minerals. n. h. w. 
Preliminary Lists of the Organic Remains Occurring in the various 
Geological Formations comprised in the South-west Quarter-sheet Map 
of the Eastern Townships of the Province of Quebec. By H. M. Ami. 
(Ann. Rept. Geol. Survey of Canada, new ser., vol. 7, pp. 113J-157J, 
1896.) This is an appendix to Dr. Ells’ report on the geology and re¬ 
sources of the S. W. quarter-sheet map of the eastern townships of Que¬ 
bec. It contains a mass of evidence upon which the geological bounda¬ 
ries of the various sedimentary, and for the most part highly fossiliferous, 
