Review of lieceat Geological Literature. 53 
.1/; Orbicular Granitefrom Quonochontogm Beach, Rhodt Island. By J. 
F. Kemp. Trans. X. Y. Acad. Sci., vol. 13, pp. 140-114. pi. 2, 1894. The 
hormal rock is a biotite granite in which are more basic spheroids two 
or three inches across and of rudely elliptical outline. The center of 
each spheroid consists almost entirely of plagioclase; toward the rim, 
biotite becomes noticeable and the spheroid is more finely crystalline; 
further out, the biotite assumes a concentric arrangement. After a very 
decidedly darker zone, the inner part of the spheroid ceases abruptly; 
outside of this is a /.one, one-eighth to one-half inch wide, formed of 
plagioclase crystals with their twin lamella' radiating from the inner 
portion. The specimen is from a boulder which the author thinks has 
not been moved far from its parent ledge. r. s. g. 
On ArgyrodiU and a new SulphostannaU "f Silver from Bolivia. By S. 
I,. Penfield. (Ame'r. Jour. Sci.. :>, vol. 47, pp. 4.")l-4o4, June, 1894.) 
The new mineral is isometric and is almost identical with argyrodite in 
all of its physical properties; the formula is Ag 8 (Sn( le) S M . Less than a 
year ago Prof. Penfield described as canfieldite a mineral of the same 
composition as argyrodite, but isometric instead of monoclinic. Since 
then the latter has been found to be isometric, so the name canfieldite 
is withdrawn and applied to this new species, — a sulphostanuate of sil- 
ver isomorphous with argyrodite. u. 8. 6. 
The Ejected Blocks of Monti Somma. By H. .1. Johnston-Lavis, Pro- 
fessor of Vulcanology, University of Naples. (Trans. Edinburgh Geol. 
Soc. vol. vi. pi. .->. pp. 314-351, pis. 13-15, 1893.) This is the first of an 
intended series of papers on these ejected blocks, the minerals of which. 
both for their beauty and variety, have made the region of Vesuvius 
so well known to mineralogists. The present paperdeals with the alter- 
ations (met a mo]-] ih ism ) to which the blocks of si rat ified limestone have 
I iee n subjected. Tin-re are three stages in t lie degree of metamorphism: 
(1) carbonized limestone, (2) saccharoidal limestone with peridote, and 
(.'!) limestone nearly or entirely replaced by different silicates, sulphides, 
and fluorides. Briefly summed up. the changes are: first, the carboni- 
zation of the bituminous contents and t heir conversion into graphite, 
almost coincident with which recrystalli/.at ion lakes place: the recrys- 
talli zation seems to have gone on withoul the rock having been fused, 
as delicate stratification, bandiug, faulting and contortion structure is 
preserved; at this stage a few grains of peridote appear; with the disap- 
pearance of i he graphite, what remains is a more or less coarse-grained 
dazzling while, saccharoidal marble: this saccharoidal marble, contain- 
ing more or less peridote, passes somewhat abruptly into a mass of peri- 
dote and white pyroxene, wollastonite, or biotite. r. s. o. 
Tvenm nyupptackta svenska klotgraniter. B,\ Helge Backstrom. (Geol- 
ogiska Poreningens i Stockholm Forhandlingar, No. (56, Bd. 16, Elafte 
.'. pp. 107-130. Fell.. 1894. With a German resume^.) Two new spheroid- 
al granites, at present known only in loose Mocks, are described from 
Kortfors and Baiungstrand, in central Sweden. The first (Kortfors) 
consists, if dark, well rounded, concentrically built spheroids in ;i sparse 
