390 The American Geologist. December, looi 
a large number of fossiliferous horizons. Mammals, reptiles, turtles, 
crocodiles, and fishes were found in large numbers. 
Among the most interesting of these discoveries is a (presumably) 
Lower Oligocene proboscidian, for which Mr. Andrews proposes the 
name Palacomastodon bcadnclU. The Proboscidia are a most c>ctra- 
ordinarj'' group in point of specialization, their tooth and foot struct- 
ure being unique in the animal kingdom. The Lower Miocene of 
Europe has long been noteworthy for the first appearance of the group 
in a highly specialized form. Mastodon angustidcns. It is of great 
interest to find that Palacomastodon presents a tooth structure of much 
greater simplicity and more generalized type than this most pririiitive 
previo'usly known proboscidian. Other members of the group were 
found, and we may henceforth look upon northern Africa as their cen- 
tre of radiation. 
The evolution of the African fauna is entirely independent, the 
animals differing from those found in deposits of the same age in 
Europe. The existence of a large and long isolated land area to the 
south is thus indicated. i. h. o. 
Uebcr die Entzvickclung dcr Silurischcn Scdimcnte in Bolicm und in 
Sudivcstcn Europas, von Fritz Frech, niit 6 fig. (Neuen Jahrbuch 
fiir Mineralogie etc., Jahrg. 1899, Bd. ii.) 
This article collates from various sources (the works of Barrande 
Bergeron Barrios Brogger, etc.) information gathered as to the 
changes of the Silurian and Cambrian sediments in various parts of 
western Europe. 
The author describes a continental area extending from nortii of 
Bohemia through France and Spain where no upper Cambrian eedi- 
■ments have been found as separating two marine areas in the N. W. of 
and the S. E. of Europe respectively. Over this isljftid by transgression 
in Lower Ordovician time the sea gradually spread introducing the 
great Asaphi and eventually the Calymmenidas into areas which prev- 
iously had only coarse sediments, conglomerates, grauwackes and 
coarse sandstones. The depression went on until abysmal forms like 
the graptO'lites and the radiolarians appeared and spread over wide 
areas, especially in England, France, and the eastern Alps as well as 
the northwestern or Scandinavian sea of that period. The article dis- 
cusses and approves of Dr. Brogger's determinations of the equiv^alent 
of the Ceratopyge fauna (Tremadac) with his interpretation of the 
genera mentioned in the works of Barrois, Bergeron, Salter and ethers 
■who have studied the faunas of this period of Palaeozoic time. 
C. F. M. 
