40 
THE GEOLOGIST. 
divisions, and therefore if tliere exist three chief divisions in the Kimme- 
ridien formation, the limits of these groups are very different from those 
■which liave been assigned to them. 
These are the opinions Dr. Contejean has striven to work out in the 
book before us, and to this end he first describes the geographical range of 
the Kimmeridge beds, through Damvant, Abbevillers, Audincourt, Mont- 
beliard, and Belfort, in a north-westerly direction ; then through the Allan 
Valley to the district of Ponentruy ; and next, south-westwards, to Long- 
velle and I'lle-sur-le-Doubs. He then describes the subdivisions, with 
their mineral characters and their characteristic fossils. These subdivisions 
are: — (1) Calca'ire a Astartes ; (2) Calcaire a Naiices; (3) Marnes a 
Astartes ; {^) Calcaires a Tej^ehratules ; [b) Calcaire a Cardium ; (6) Cal- 
caii^es et Marnes a Pteroceres ; (7) Calcaire a Corhis ; (8) Calcaires a 
Mactres ; (9) Calcaires et Marnes a Virgules ; (10) Calcaire a Diceras. 
A section of his book is now devoted to detailed lists of the respective 
faunas of each of these subdivisions, and to comments upon them. After 
a summary of the facts thus brought forward, he tabulates his results in 
the following manner : — 
Etage Kimmeeidien. 
lY. Groupe Neeineen . Subdivisions to be made out. 
{ 10. s. gr. Calcaire a Diceras. 
mn^^ „ T^,„^_^,^,, / 9. Calcaires et Marnes a Virqules. 
. (jrrOUpe V IBGULIEN . \ o 7 • ^ v , ^ 
^ 8. Calcaire a Mactres. 
[ 7. Calcaire a Corhis. 
f 6. Calcaires et Marnes a Pteroceras. 
II. Groupe Pteeoceeien 5. Calcaire a Cardium. 
I 4. Calcaire a Terehratules. 
f 3. Marnes a Astartes. 
I. Groupe Astaetien . ( 2. Calcaire a Natices. 
\ 1. Calcaire a Astartes. 
The last question then remains — what are the limits of the Kimmcridien 
as thus defined? These Dr. Contejean asserts are exactly indicated. The 
Ximmeridge division terminates the Jurassic marine series, and is naturally 
arrested by the Purbeck beds, which most geologists have considered 
cretaceous, but which the author considers M. Coquand has rightly asso- 
ciated with the Jurassic formation. The inferior limits he sets forth as 
equally easy to establish, the Kimmeridge division commencing where 
the mass of fossil corals ends, or immediately above the Diceras beds of 
the Coralline Oolite. 
The fourth section of his work Dr. Contejean devotes to the " Parallel- 
ism of the Formation," and notices the characters presented in the Medi- 
terranean basin. Straits of Dijon, Anglo-Parisian basin, and the Pyrencan 
basin. This is followed by a fifth portion, with geological sections and a 
general list of the fossils of the whole formation. The remainder of the 
book, amounting to a hundred pages, is taken up with detailed descriptions 
of new or critical species of shells, w hich are illustrated by twenty-four ad- 
mirable lithographed plates, very carefully and accurately drawn. The 
book is moreover illustrated by three plates of sections and stratigraphical 
diagrams of the ranges of the various groups of fossils. 
We have, in former reviews, had occasion to speak well of the geological 
works published by M. Eothschild, but of none we have yet noticed could 
we desire to speak in higher terms of praise than of Dr. Contejean's admi- 
rable monograph before us. 
