H flDontbl\> journal of IRaturai Science 
Vol. II., No. 17. 
MALTA, OCTOBER 1st. 1892. 
' - Per annum 
By post 5/- 
CONTENTS. 
— — Pag. 
1 Supposed Quaternary and since submerged Volcano 
at Naples — G. Jervis, F.G.S. 251 
2 On Tryonx Ragusensis and T. Melitensis 25?ji. 
3 The Phoenicians in the Mediterranean 251 
1 On the Occurrence of Black Limestone in the Strata 
of the Maltese Islands— J. H. Cooke, F.G.S., ecc. 255 
5 Fight ing Mice with a Bacillus 257 
G Teeth Food 257 
7 The Rolf Mon of the Structure of Rocks to the condi- 
tion: of their formation— H. J. Johnston Lavis, 
M.D., F.G.S. 257 
8 A Strange March to the Sea 259 
9 “Left Handed" Snails 260 
10 The Depths of the Mediterranean and Black Seas — 
R. Beynon. F.U.G.S. 2G0 
11 Prehistoric Itemes 2G3 
12 ± Votes and News:- British Association— Tempera- 
ture of the Atlantic— Mount. Etna— Birds. V. In- 
sects in Malta— The Malta fig-tree, ecc. eee. 2G5 
13 Correspondence:- Monkey talk— Sur. Capt. Hughes 2G6 
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17 
Supposed Quaternary 
and since submerged volcano 
of Mergellina, at Naples. 
On entering the Bay of Naples by steamer the 
first thing which must have struck every geologist 
— leaving aside Vesuvius for the present — is the 
line of flat topped hills stretching along the north- 
ern shores of the Bay, from Cape Posillipo to the 
Chiatamone, above theCastel dell’Uovo, their sum- 
mits in no place exceeding from 1 60 metres to 200 
m., in height except at the Castel Sant’Elmo(224 m.) 
while they extend inland from the Yomero to the 
culminating point at the old Camaldoli convent, 
above Gianura (455 m.) These hills are essentially 
constituted of irregular strata of ochreous-yellow 
volcanic tufa of va rious tints, passingon the one side 
to pale yellowish-white, and on the other to yel- 
lowish brown. This tufa is accompanied by fre- 
quent alternating beds of extremely line volcanic 
ashes, and others often exclusively formed of im- 
pure-white or ash-gray pumice stone in angular 
pieces, ranging from less than a quarter of an inch 
to several inches across, and adhering slightly 
together, though easily separated by the hand. 
Fragmentary pumice stone also exists in a certain 
proportion as a constituent part of the volcanic tufa 
itself, parting in general in such case of the colora- 
tion of the rock in which it is imbedded, being of a 
yellowish-brown, and only in some places white, 
for instance near Biedigrotta. Sometimes the pu- 
mice stone is dark yellowish-brown, this variety, 
as well as the paler kind, being much decomposed, 
or what might be called in ordinary language 
rotten so as to crumble when an attempt is made 
to detach it from the enclosing rock, for it is only 
when the pumice stone retains its original whitish 
or asli- gray appearance that it preserves any con - 
I have for many a long year been led to be- 
lieve that this tufa w r as produced by a volcano 
situated at a short distance from the Mergellina, 
but now submerged and no longer recognizable, 
