TRANSACTIONS OF THE SECTIONS. 69 
ruginous sandstone, horizontally stratified. This formation seems also to extend 
- round the whole Gulf of Carpentaria, and to the Victoria River. The sandstone 
abounds in ferruginous concretions, which sometimes compose its entire mass, 
which then looks like the refuse of an iron furnace, or part of alava stream. These 
masses form the headlands and projecting points of the cliffs. On account of their 
similarity to the tertiary sandstones of Port Phillip, the author infers their simi- 
larity in age. In concluding, the author remarks the parallelism of all the known 
mountain chains in Australia, the majority being N.N.E. and S.W., and none vary- 
ing more than two points from north and south. He also cites the opinion of 
Capt. Sturt, that one vast desert plain stretches from the great Australian Bight to 
the Gulf of Carpentaria; and observes that the only great extent of country unac- 
counted for, is on the north-west side, where the range between Cambridge Gulf 
and Buccaneer’s Archipelago may rise into some importance in the interior. 
Notes on Geological Phenomena in Africa. By J. Duncan. 
Granite abounds in the Mahra country, which is a part of the King Mountains, 
N.E. from Abomey. The mountains run in curved lines towards the N.W. and 
SE. The lesser ranges, which border the King Mountains, are stratified, often 
dipping east (15° to 20°), and farther offt he beds are horizontal. They are all of 
the granitic or gneiss character. 
On the mountain Kpalloko, the loftiest from its base in the Mahra country, 
are several towns. The escarpment on the north is perpendicular. The rocks are 
formed in curved beds. 
About 100 miles beyond the mountains, in lat. 11° 30’ N., are calcareous and 
ferruginous springs; and sulphur (Kao) is found abundantly in the mountains. 
[This communication was presented to the Nat. Hist. Section. ] 
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Note on Graphic Granite. By A. C. G. JoBert. 
The inspection of several samples of graphic granite have led me to the conclusion, 
—Ist, that there are cases where it can be successfully demonstrated that during the 
process of the refrigeration of the granite, the crystals of quartz were formed first 
in the middle of the felspathic melted matter. 
_ 2ndly. That during the subsequent process of the consolidation of the felspar, 
the quartz crystals remained for a time in a gelatinous state. 
_8rdly. That the circumstances which have accompanied the production of graphic 
granite, such as the movements of the mineral matter injected in veins, and lateral 
pressure, have modified the crystals of quartz, so as to destroy, partially, the pris- 
matic regular shape, in flattening them, and sometimes imprinting upon them forms 
corresponding to the felspathic crystallization. 
4thly. That it is to these modifications in the form of the prismatic crystals of 
quartz that the particular aspect of the graphic granite is due. 
These facts may lead to important deductions: for instance, if it is clearly de- 
monstrated that in the granitic masses the crystals of quartz have existed in a ge- 
latinous state, whilst the felspar passed from the liquid to the solid state, this cir- 
_ cumstance will explain many accidents in the granitic envelope, such as the forma- 
tion of quartz veins and dikes in natural contemporaneous fissures, through the 
pressure of superincumbent masses, and even also the formation of felspathic dikes 
in a granite where the quartz was predominant, if the fissure has been produced 
in a yielding mass, when the felspathic elements were still in a liquid state. 
_ Notices of Natural History Observations made since last Meeting bearing upon 
Geology. By Professor E. Forses. 
The principal facts communicated were the following :—1. The discovery, in a 
_ living state, of several species of Mollusca hitherto known in this region only as 
_ fossils. Leda pygmea, Arca raridentata, and Astarte Withami, were the instances, 
all taken by Mr. M‘Andrew and Mr. Forbes in the British seas. They had also 
- taken the Turbinolia Milletiana, till lately a characteristic miocene fossil, alive, off 
_ the Land’s End, and had proved the animal to be scarcely different from Caryophyllia. 
2. The dredging from deep sea at a distance from land, of several species known 
