932 The American Naturalist. [ November, 
Traquair, R. H.—The Extinct Vertebrata of the Moray Firth Area. Reprint 
from J. A. Harvie-Brown and T. E. Buckley’s “ Vertebrate Fauna of the Moray 
Basin.” Edinburgh, 1896. 
Warp, J. H.—Prophets, Saints and Scientists, the Oracles of the Ages. 
Dover, New Hampshire, 1896. From the author 
WETTSTEIN, R. v.—Monographie der Gattung Euphresia. Arbeiten des botan- 
ischen Instituts der k. k. deutschen Universitit in Prag, No, IX, Leipzig, 1896. 
From the author. 
WHITEAVES, J. F.—Revision of the Guelph Formation of Ontario, with De- 
scriptions of a Few New Species 
——Systematic List, with References, of the Fossils of the Hudson River or 
Cincinnati Formation at Stony Mountain, Manitoba. E Fossils, Vol. 
HLL, Pt. s a 1895. From the Geol. Surv. Cana 
Woop D, A. S.—Catalogue of the Fossil Fishes in a British Museum. 
Pts TEL Mpe 1895. From the British Museum. 
General Notes. 
MINERALOGY AND CRYSTALLOGRAPHY: 
Etched Figures on Some Minerals.—Traube’ brings into 
deserved prominence the value of the method of etching, and gives the 
results of an extended series of experiments on the etched figures of a 
number of minerals. He mentions especially those cases in which the 
etched figures indicate a higher symmetry than that occasionally shown 
by the geometrical development of the crystal form. He evidently 
lays more stress on the etched figures of crystals than on the occasional 
growth of planes corresponding with a lower symmetry. K F and 
K F, H F are mentioned as giving good results in many cases where 
the problem is to etch one of the more refractory silicates, and a cau- 
tion is given that care must be taken in the use of such powerful 
reagents. 
On cuprite etched figures were produced by H,SO,, HCl, HNO, and 
KOH, dilute HNO, giving the sharpest figures. The etching indicates 
a holohedral regular symmetry, notwithstanding that Miers has o 
eS faces of the form (986) in a position suggesting gyroidal hemi- 
hedris 
Piseeantis gives sharp figures with hydrochloric, sulphuric, nitric 
and acetic acids, also with the caustic alkalies, all pointing toward holo- 
1 Edited by Prof. A. C. Gill, Cornell University, Ithaca, N. Y. 
2? Neues Jahrb. B. B. X, pp. 454-469, 1896. 
