182 General Notes. [February, 
theory of Darwin, but to show that in some cases, at least, coral 
reefs are but the summit of an elevation formed by other agen- 
cies. In cases of subsidence the reefs are thick, while in regions 
of elevation, as in Florida, the coral reef is but a thin crust top- 
ping a bank of deposited matter. 
MINERALOGY". 
ITE—A New Zeouite.—A. Arzuni describes a 2” 
lite from St. Andreasberg, in the Harz, which, while closely 1e 
sembling gruelinite in form and physical properties, contains ah 
and magnesia in place of pativis of the aluminum and lime, at i$ 
to be regarded as a new variety of gruelinite. It 1s describ Ke 
occurring in small crystals upon calcite, containing 1n their 10 
the rhombohedron, scaleushedron and hexagonal prism, and A 
sessing a prismatic cleavage, and a hardness of between 3 an 4 
The composition is : : 
BO) MAG, FO) Cad mo h H,0 
3.8 4-5 20.2 = 108 
51.2 12.0 77 I.I 
and the formyla 
(Mg Na,), (Al, Fe,), Sy Og + 13 H:O com 3 
is adduced, the mineral being regarded as a magnesia-Iron = 
elinite. of the 
It is named from Dr. A. von Groddeck, the director % 
museum at Clausthal, in which the specimen was toune. fot 
HERDERITE FROM Maine.—Mr. U. E. Hidden, well kno the 
his mineralogical discoveries in North Carolina, announce a 
probable occurrence of the rare mineral Herderite at eas at t0 
Maine. The crystals are short, truncated prisms, trans ae grav 
translucent, colorless or faintly yellowish. Hardness 5 ee It re 
ity 3. The crystals are orthorhombic with TAT = I? sent 
sembles topaz in form and color, but has neither the clea 
the hardness of that mineral. An analysis is now beine 
Professor E. S. Dana gives some crystallogr aphic. meas 
which closely approximate the angles of herderite. 
Recent METEORITES.—A large meteorite fell la 
near Brescia, Italy. It was about half a metre long and 0" 
ical shape. It buried itself a metre deep in the cat . 
the grass in the neighborhood, and when dug out was “although 
and the smell of sulphur was distinctly noticeable. rection, 
the meteorite passed through the air in a S. S. E. p ection. 
forced its way into the earth obliquely in an opposite a purst # 
About a year earlier, in February, 1882, a great nee ugh 
_ a cloudless sky in Transylvania. A large ball of fire see? d 
1 Edited by Pro i atural Scien 
delphia, to pace es he lanis coreg Sl er be sent 
Am. Four. Sci., jan., 1884, p 7% 
