File:The Quarterly journal of the Geological Society of London (12733843075).jpg

F. G. H. PRICE ON THE GAULT OF FOLKESTONE. 345
Bed I.
The junction-bed separating the Folkestone -beds of the Lower
Greensand from the Gault consists of a line of nodules of sulphuret
of iron, which is about 1 foot 3 inches in thickness. This is
succeeded by a band of dark greensand, containing two lines of
phosphatic nodules, in which nodules Ammonites interruptus and
pieces of wood bored by Pholadidea sanctce-crucis, Pictet et Camp.,
are found; many of the fragments of Ammonites, Inocerami, &c.
which are plentiful in this band are sprinkled over with small
spicules or crystals of selenite. In no other band throughout the
Gault has this ever been observed. The dark greensand seam goes
off suddenly into Gault, with a line of phosphatic nodules traversing it.
These nodules of phosphate of lime arise, I presume, from the decom-
position of the remains of mollusca, fish, saurians, &c.
The fossils of this junction-bed are usually in the condition of
rolled casts, and of a fragmentary nature. The following are some
of the most ordinary forms met with

—
Palaeocorystes Stokesii, Mant.
Inocerarnus concentricus, Park.
Nucula pectinata, Sow.
Pecten, sp.
Pholadidea sanctas-crucis, Pict. et Camp., in wood.
Teredo-tubes.
Trigonia Fittoni, Besh.
Dentalium decussatum, Sow.
Pyrula, sp.
Ammonites interruptus, Brug.
Hamites attenuatus, Sow.
H. rotundus, Sow.
Belemnites minimus, List.
Nautilus, sp.
Vertebrae of saurians and fish.
Mr. Gardner has obtained a species of Hippurites and Buccinum
gaultinum from this bed.
The above-mentioned fossils are mostly found more or less in-
crusted with phosphate.
Upon many pieces of Ammonites, nearly all of which are Ammonites
interruptus, I have found specimens of Plicatula pectinoides, Pecten
quinquecostatus, Trocliosmilia sulcata, and a species of Nucula allied
to obtusa, all with the shell on, apparently indicating that they were
contemporary with the formation of the bed, which appears to have
been derived from some deposit now destroyed.
Whilst examining this bed last October at Copt Point, I met with
a piece of Ammonites Roissyanus, D'Orb., in situ, imbedded in phos-
phate

this is a very rare Ammonite to meet with at all, and
especially in the Lower Gault, as it belongs to the Cristati, or
crested group of Ammonites, which are characteristic of the Upper
Gault.
I also found a fragment of a very large smooth Ammonite, deeply
grooved, which I cannot at present assign to any