Be i Re eS 
1883. ] Recent Literature. 521 
with hydrofluoric acid until the triclinic pyroxene was almost en- 
tirely dissolved. The rhombic pyroxene was then analyzed and 
found to possess the composition of hypersthene, The isolation 
and chemical analysis of the rhombic pyroxene was performed 
by Mr. W. F. Hillebrand of the U. S. Geological Survey. 
The conclusion drawn is, that a large proportion of the sup- 
posed augite is hypersthene in the andesites. The paper is an 
important contribution to the micro-mineralogy of andesite, and 
its publication in a completed form is awaited with interest. The 
sci chemical analysis of the andesite was made by Hille- 
rand : 
Sp. Gr. SiO, Al,O, F&O, FeO CaO MgO Na,O 
2742 «56.19 «16.117 4.919 © 4.433. 6.996 4.601 ~— 2.9618 
TEO Mno PO, Cl H,O Total, 
8368 trace 0.266 0.022 1.028 99.901. 
—WM. E. W. 
Year Book or THE GERMAN MaracorocicaL Socrety'—This 
excellent periodical has now concluded its ninth year of publica- 
tion, a fact upon which malacologists may well congratulate 
themselves. Those only who have been personally engaged in 
upholding a periodical devoted to a speciality, addressed to a 
small audience of naturalists whose interest in their favorite study 
'S too often counterbalanced by deficiencies of income,—the 
alone can realize what a successful nine years’ struggle implies. 
The society whose organ it is, is partly an outgrowth from the 
enckenbergian Museum of F rankfurt, its curators, students and 
cation more worthy to be the organ of German Malacology 
f mentioned journal after an honorable and apparently success- 
tul career of 
Edit der Deutschen Malakozoologischen Gesellschaft, 1882. Frankfurt am 
ed by Dr. W. Koper: M. Diesterweg. 
