304 APPENDIX. 
GASTEROPODA. 
The following land and fresh-water shells are from the Formations belonging to the Uppermost or 
Newest Tertiaries of Great Britain. These shells are all, with the exception of four, undoubtedly identical 
with species still in existence in England, and it is thought an insertion of their names alone, with a 
reference to where they have been recently well figured and described, will be sufficient. The exceptions, 
though here extinct, are still existing in other parts of Europe; and as they were formerly inhabitants of 
where their remains are now found, they claim a place in the Monograph of the Upper Tertiaries of the 
British Isles. 
I am indebted to Mr. John Brown, of Stanway, for the list of species from Copford and from Fisherton. 
lJatus and other decollated, or rather decapitated, shells, which appeared to have become so from the want 
of the necessary connection between the shell and the more vital parts. It is to Dr. Fleming, perhaps, 
that the real priority of the idea should be awarded. In his ‘Philosophy of Zoology’ there is a very 
significant passage, where he speaks of the vitality of the shell when in intimate contact with the fluids of 
the animal, foreshadowing there the belief, now generally entertained, that the calcareous portions of the 
Mollusca are far from being inert matter, secreted merely as protective coverings to the softer parts (a 
considerable section being wholly destitute of such coverings), but that they are truly constituent and 
integral portions of the animals themselves, only with a larger amount of inorganic elements. 
It is well known that, in some of the extinct species of Cephalopods, the tube is protected throughout 
its entire length by a rigid, continuous, and inflexible covering, and one can scarcely refrain from an 
expression of astonishment that naturalists, who have purposely studied, and largely published their views 
upon the Nautilus and its congeners, should not have discerned the now presumed use of the siphuncle. 
If seen, it is perhaps still more extraordinary that this silver cord should have had with it so little 
explanation. 
My friend Mr. Edwards has (I think wisely) left the determination of the claim to priority to the 
judgment of the members; but an ulterior question arises, which is, whether the paragraph quoted by 
Mr. Edwards in his address amounts to more than the suggestive passage by Dr. Fleming, similar in its 
purport, to which I have referred. 
The two passages are here subjoined :— 
«The shell cannot be considered as dead matter so long as it remains in connection with the living 
animal. In those animals in which the shell is external, there are muscles which connect the animal with 
its external surface, and the bond of union being a substance soluble in water, the muscles can be detached 
by maceration. The analogy between shell and bone is here obvious, although in the one case the con- 
nection between the muscle and the bone is permanent, in the other between the muscle and the shell 
temporary, or frequently changed during the life of the animal. But the vitality of the shell, if I may use 
the expression, is demonstrated from the changes which it undergoes when detached from the animal. The 
plates of animal matter harden, the epidermis dries, cracks, and falls off, and in many cases the colours 
fade or disappear. We confess ourselves unable to point out the means employed by the animal to prevent 
these changes from taking place by any process similar to circulation.”’—PAil. of Zool., by Dr. Fleming, 
vol. ii, p. 405, 1822. 
“Whatever additional advantage the existing Nautilus might derive by the continuation of a vascular, 
organized membranous siphon through the air-chambers, in relation to the maintenance of vital harmony 
between the soft and testaceous parts, such likewise must have been enjoyed by the numerous extinct 
species of the Tetrabranchiate Cephalopods, which, like the Nautilus, were lodged in chambered and 
siphoniferous shells.”’—Lectures upon the Invertebrata, by Professor Owen, p. 331, 1843. 
