
814 The American Naturalist. (September, 
The whole number of Testudinata recorded by Dr. Boulenger is 
195. Perhaps there are a dozen species omitted. Of the Crocodilia 
23 species are recognized.—E. D. Cope. 
Frazer’s Mineralogical Tables.2—The object of Dr. Frazer’s 
tables is to enable the students to determine the nature of the most 
important minerals without recourse to blowpipe analysis. As is webl 
known, the first edition was a translation of Dr. Weisbach’s ‘‘ Tabellen.’ 
In the third edition but little of Weisbach’s original descriptions 
remain. Except the plan, the entire contents of the little book are 
Dr. Frazer’s, so that the volume as it now stands is essentially a new 
production, in which are incorporated many of the most important 
portions of Groth’s chemical tables and Weisbach’s latest determina- 
tive tables. The arrangement of the tables is briefly as follows: The 
minerals are divided in accordance with luster and streak. These 
groups are printed together, and in columns opposite the names of the 
various members of each group are given their hardness, tenacity, 
crystal system and habit, cleavage, chemical composition, density, 
paragenesis, and a few blowpipe reactions in rare cases. With its aid 
there should be almost no trouble in deciding the name of any com- 
mon mineral. The tables are especially valuable for field determina- 
tions. They are bound flexible cloth, and are of a convenient size 
for carrying in the pocket.—W. L. B. 
3Tables for the Determination of Minerals. By Persifor Frazer. Third edition. 
Philadelphia, J. B. Lippincott Company, 1891, pp. IX 



