728 
completed alone; and that he has been able to 
do this while his chair in the faculty of science 
at Lille (Academy of Douai) was demanding 
the constant and fatiguing work of lectures and 
preparation, and his arduous labors in Brit- 
tany under the geological survey of France 
suffered no interruption! 
Without the experience which he gained, both 
in the field and in the art of publishing, by his 
important and now often quoted ‘‘ Recherches 
sur le terrain cretacé supérieur de |’ Angleterre 
et de l’Ivlande,’’ which won him his doctorate 
from the University of France, he would hardly 
have been so successful in this last book. Both 
works begin with historical notices and bibliog- 
raphies ; but in the latest the first four pages 
are devoted to a veritable history of the labors 
of his predecessors, rather than to a mere list 
of their books. At the end of this, however, 
there are nearly four pages of titles rained 
upon the reader, as if Dr. Barrois were anxious 
to terminate this part, and get at his subject. 
Accompanying this large and handsome quar- 
to is an atlas in the same form, which contains 
twenty plates reproduced in the best style of 
art at the present day. The first three of 
these are colored plates, representing ten thin 
sections of rocks under the microscope and in- 
polarized light. Each plate is conveniently 
covered by a thin tissue sheet containing the 
outlines of the constituent minerals, with the 
letters and figures necessary for indentifying 
them. Following these are fourteen plates of 
fossils, of which four are from the hand of the 
author ; nine were drawn by the lithographer, 
Mr. C. Rogghé; and one is a phototype from 
the Alteliers de reproductions artistiques in 
Paris. The last three plates are in order: one 
of vertical sections, one of section sketches, 
and one of pure sketches, on which latter in- 
teresting and important geological phenomena 
have been marked. Viewed as a whole, the 
artistic work is as perfect as any set of illustra- 
tions of scientific matter which the writer re- 
remembers to have seen. Where fault is so 
hard to find, he may be pardoned here for 
mentioning the only additions which it seems 
to him could have made the plates clearer; viz., 
a note of the amount of enlargement of the 
figures of plates ii. and iii., on the pages oppo- 
site those plates. Plate i. is thus provided. 
The first part of the subject of this review 
(161 p.) is devoted to lithology. 
esting and valuable, and will do much to in- 
crease the reputation of the author. It treats 
of the general and microscopic characters of the 
sedimentary rocks, including schists, phyllites, 
quartzites, limestones, and mimophyres; and 
SCIENCE. 
It is inter- 
4?) eee * ~~. ea. 
; . 
[Vou. IIL, No. 71. 
the crystalline massive rocks, comprising 
granite, quartz porphyry, diorite, diabase, and. 
recent quartz-bearing kersantite. The schists 
are of every age, from the Cambrian to the 
carboniferous; and he divides their mineral 
ingredients into two classes, — those which were 
clastic, and prior in origin to the consolidation 
of the rocks ; and those which were secondary, 
or crystallized out during the consolidation. 
The first class includes quartz, felspar, and 
white mica; the second, quartz, rutile, tour- 
maline, white mica, and chlorite. The term 
‘mimophyre’ is given by Barrois to a series of 
felspathic, porphyritic, and schistose rocks, 
which he thinks were formed from volcanic 
ashes and detritus, —the same as most poro- 
ditic felsites are known to have been formed. 
The mimophyres are found associated with the 
sedimentary schists, quartzites, and phyllites, 
and belong to the Cambrian, Silurian, and 
Permian. 
Of the plates, it is sufficient to state that 
they were made by Jacquemin, who prepared 
those for Messrs. Fouqué and Lévy’s ‘ Miné- 
ralogie micrographie.’ 
The second part treats of the paleontology 
of the Cambrian and Silurian (chap. i.), and of 
the Devonian and carboniferous (chap. ii.), and 
occupies 217 pages of very interesting matter ; 
to which, however, it will be impossible here 
to make more than the briefest allusion. We 
learn from a prefatory note, that Dr. Barrois 
has succeeded in collecting three hundred and 
eighty-five species of fossils from the field of 
his labors in this part of Spain. Of these, thir- 
ty-nine are new species, which we owe to his 
research ; viz., three in the Cambrian and Silu- 
rian, twenty in the Devonian, and sixteen in 
the carboniferous. Thesyllable‘ Barr.,’ affixed 
to many others, is apt to lead the hasty reader 
to ascribe these also to him ; but the abbreviation 
is for Barrande, and not Barrois. The author’s 
note (p. 177) on the right of precedence of 
Professor Haldeman’s Scolithus over Ronault’s 
Tigillites is a model of impartial justice and 
scholarly treatment of the subject. 
Following the detailed description is a ré- 
sumé (pp. 359 to 385) containing considera- 
tions by Dr. Barrois on the genera and species 
just referred to, with special regard to their 
parallelisms ; and the chapter is concluded by 
speculations on the conditions under which the 
deposits have been formed. In the following 
chapter (ii.) the same method is applied to the 
fossils of the Devonian and carboniferous. 
The third part is devoted to the stratigraphy, ~ 
including, of course, the description of cross- 
sections. It is no fault of the author that this 
