388 
Royal Society. 
ROYAL SOCIETY. 
March 23, 1848. — “ Observations on some Belemnites and other 
fossil remains of Cephalopoda, discovered by Mr. Reginald Neville 
Mantell, C.E., in the Oxford Clay, near Trowbridge in Wiltshire.” 
By Gideon Algernon Mantell, Esq., LL.D., F.R.S., Vice-President 
of the Geological Society. 
The author states, that a line of railway now in progress of con- 
struction to connect the large manufacturing town of Trowbridge 
with the Great Western, being part of the Wilts, Somerset, and 
Weymouth line, traverses extensive beds of the Oxford clay of the 
same geological character as those at Christian-Malford in the same 
county, which furnished the remarkable fossil cephalopods described 
by Mr. Channing Pearce under the name of Belemnoteuthis, and by 
Professor Owen (in a memoir which received the award of a Royal 
Medal of this Society), as the animals to which the fossils commonly 
known by the name of Belemnites belong. 
The son of the author, Mr. R. N. Mantell, being engaged in these 
works under the eminent engineer Mr. Brunei, availed himself of the 
opportunity to form an extensive and highly interesting collection of 
the fossils of the Oxford clay, and other oolitic deposits cut through 
or exposed by the engineering operations. Among those transmitted 
to the author are many illustrative examples of Belemnoteuthes and 
Belemnites ; some of which confirm the opinions entertained by the 
late Mr. C. Pearce, Mr. Cunnington, and other competent observers, 
that the body and soft parts, with the cephalic uncinated arms, &c. 
of cephalopods, obtained from Christian-Malford by the Noble Pre- 
sident and Mr. Pearce Pratt, and referred by Professor Owen in the 
memoir above-mentioned to the Belemnite, belong to a distinct 
genus — the Belemnoteuthis. 
The author describes and figures several perfect examples of the 
phragmocone of the Belemnoteuthis, and institutes a comparison be- 
tween them and a beautiful example of the phragmocone of a belem- 
nite occupying the alveolus of the guard; and defines the essential dif- 
ferences observable in the form and structure of these chambered cal- 
careous cones. He especially points out as distinctive characters of 
the phragmocone of the Belemnoteuthis, two fiat longitudinal ridges 
which extend upwards from the apical extremity, and the granulated 
and striated external surface of the epidermis. The phragmocone 
of the Belemnite has a smooth surface, is destitute of any lon- 
gitudinal ridges, and terminates at the apex in a very fine point, the 
axis being in an oblique direction. 
The author next describes a remarkable specimen of a Belemnite, 
twenty- two inches in length, in which the osselet or guard, phrag- 
mocone, and capsule or receptacle, are preserved in connexion. In 
this fossil is demonstrated, for the first time, the upper or basal ter- 
mination of the phragmocone, with two elongated calcareous pro- 
cesses extending upwards from the margin : these are analogous in 
form and position to the prolongations from the peristome of the 
