Geology and Palcontology. 831 
phase of the Jurassic, came the marine invasion corresponding to 
the deposition of the Cretaceous beds ; sedimentation then continued 
quietly and tranquilly during the Tertiary period, at the bottom of 
a sea at first open to a large extent and communicating freely with 
the ocean, but the area of which was always diminishing, until in 
the Sarmatian epoch this Mediterranean became closed, and was 
gradually converted by evaporation into distinct sheets of water, 
the remnants of which still remain and diminish under our own 
observation. During these ages the great mountain border of the 
t gained in height and in development. The Pliocene is at its 
summit intimately connected with the Aralo-Caspian deposits, 
which are chiefly composed of the debris of the Cretaceous and 
Tertiary strata, the slight cohesion of the older deposits facilitating 
greatly the: disintegration effected by atmospheric agencies. The 
Aralo-Caspian fossils belong to species that now inhabit the Caspian 
and Aral Seas, and their nature and mode of distribution is such 
that, taken in conjunction with what is known of the existing 
Caspian fauna, it is possible to ascertain the exact circumstances in 
which the sediments were laid down; since all the species except 
Cardium edule and Lithoglyphus caspius live near the coast, at 
depths never exceeding fifteen metres. The Aralo-Caspian Sea 
Caspian deposits. The facts indicate that in the Aralo-Caspian 
epoch the Oxus, taking in the Khiva region the course of the 
from the north and northeast have transformed into deserts the dry 
beds of the ancient lakes, and have formed those long ranges ot 
ane called Barkhans that cover such vast spaces throughout 
urkestan, 
RÜTIMEYER ON THE CLASSIFICATION OF MAMMALIA, AND 
ON AMERICAN TYPES RECENTLY FOUND IN SWITZERLAND.— 
* Ueber einige Beziehungen zwischen den Satigethierstémmen alter 
ii neuer Welt. Erster Nachtrag zu der Eocenen Fauna der Eger- 
ingen ; von L. Rütimeyer; Zurich, 1888. Abhandl d. Schwiez. Palæon- 
tol. Gesselsch. Bd, XV. 
