NEWBOLD ON THE GEOLOGY OF EGYPT. Sar 
the Red Sea, and the part of the Mediterranean so nearly adjoin- 
ing on the Libyan coast, possess only two forms in common out of 
the 120 species of Anthozoa, viz. Actinia Tapetum and 4. Mesem- 
bryanthemum ; and he remarks, that among living genera of corals of 
the Red Sea, that of Strombodes excites peculiar interest, having 
previously been found only in the fossil state. It affords a key to the 
structure of the remarkable Cyathophylla, differing from the view 
hitherto entertained, and rendering it quite clear that the internal 
central star of the encased forms is not a young one, but the oldest, 
or mother-star, which is often surrounded by broad radiated mantle- 
folds, productive of buds. Out of fifty-four new species of Polytha- 
lamia derived from the two seas, twenty-seven are peculiar to the Red 
Sea, and seventeen only are common to both. On the other hand, 
the Rotalia Beccarti, which composes the Italian hills, only occurs 
singly, and very rarely in the Red Sea, and was nowhere found on the 
Libyan and Syrian coasts. 
Recent Rocks in process of formation.—On the shores of the 
Red Sea and Mediterranean a rock-formation is still in progress, 
composed of sand, gravel, corallines, fragments of older rocks, weed, 
bits of wood and pottery washed up by the sea, and cemented toge- 
ther by carbonate of lime slightly coloured by oxide of iron. The 
stone thus formed varies from a loosely-agglutmated conglomerate to a 
light brown, compact travertin. It occurs from an inch to 3 or 4 feet 
in thickness, and sometimes alternates with thin, loose layers of 
shingle. On the west shore of the Red Sea I have observed it at five 
or six feet above the high-water level, overlying the raised coral beach. 
It sometimes encloses bones of camels, fish, &c., still containing animal 
matter. A considerable deposition of carbonate of lime appears to be 
at present going on in certain parts of the Mediterranean and Red 
Sea. At Alexandria, in the Saracenic fort of the Pharos, in 1840, I 
observed an old iron cannon, coated with rust, which, I was informed, 
had not many years back been dragged up from the bottom of the 
sea in the harbour. The bore, which was of considerable calibre, 
had been filled up with a compact, travertin-like limestone, coloured 
and hardened with the oxidized iron of the interior of the gun, which 
had become so corroded and intimately blended with the carbonate of 
lime as to assume the appearance of perfect fossilization. On the 
shores of Sicily, Greece, Asia Minor, and of Aden, near the Straits of 
Babelmandel, I have remarked similar marine calcareous formations 
in progress ; and at Rhodes, six feet above the present high-water 
mark, I observed a calcareous conglomerate imbedding fragments of 
ancient pottery, shells, and littoral pebbles of scaglia limestone, gneiss, 
basalt, serpentine, and porphyry. 
In the valley of the Nile, on the plain of Benihassan, myriads of 
nummulites, washed from the overhanging limestone cliffs, are par- 
tially re-cemented together by calcareous matter deposited by drainage- 
and spring-water, and alternate in horizontal layers with clay, sand, 
and gravel, having an aggregate thickness in some places of upwards 
of 30 feet. In the valley of Kossier, near the sea-coast, beds of 
gravel and detritus are in process of being cemented together by iron 
and lime deposited by infiltration from drainage-water, which derives 
