378 REVIEWS 
estuarine sediments. Accumulations of wind-blown material no doubt 
took place on the land. Judgment based on paleobotanical evidence has 
previously correlated the Triassic system with the European Keuper, 
but the occurrence of Ptycholepis Marshi (Newberry) in accompaniment 
with Semionotus, Catopterus, and the Crossopterygian genus Diplurus 
has led to the assignment of the Newark to a horizon that corresponds 
in a general way to the interval between the Muschelkalk and the Lower 
Keuper of European marine Trias. The author has discussed the 
significance of the fauna but has not recognized the generally accepted 
classification of the geological time-scale. 
EeAess 
Geology and Ore Deposits of the Index Mining District. By 
CHARLES E. WEAVER. Bull. 7, Wash. State Geol. Survey. 
120, OBS jollse 97. 
A brief discussion of the physical history of the region is given with 
the general geology. The oldest rocks are provisionally assigned to the 
Carboniferous, but, like most of the older rocks of the region, they are 
highly metamorphosed. Much of the geological record is obscure. Some 
good mine maps add to the clearness of the report. 
BAGS: 
Geology and Ore Deposits of the Meyers Mining District, and Geology 
and Ore Deposits of the Oroville-Nighthawk Mining District. 
By JosepH B. Umptesy. Bull. 5, Wash. State Geol. Survey. 
Bp tO7 ees ny en plsice 
A reconnaissance report on the general geology and ore deposits of 
these areas; brief description of the various mining properties are 
included; unfortunately no index map accompanies the bulletin. 
Ee Ags 
