On the Genus Nerinea and its Stratigraphical distribution in the 
Cotteswolds. By KH. Wircuett, F.G.S. 
The long spiral shell known as the Nerinea presents in its 
structure several curious and original features. It may be thus 
described :— 
Shell sub-cylindrical, sub-conical, or conical; length from 
one to eight inches; apex usually acute; surface plain or 
ornamented; aperture subquadrate, terminating in a channel, 
which is short or produced, and curved backward; columella 
solid or perforate, with 1—4 folds, outer wall with 1—3 
folds, posterior wall 0—1 fold; the folds simple, bifurcated, or 
angulated ; subsidiary minute folds also occur. 
The surface of most of the species found in the Inferior 
Oolite is in the young form encircled by faintly marked rings, 
which disappeared with age, so that about one half of the shell 
is ornamented and the other half is plain. The species occurring 
in the Great Oolite and succeeding strata are usually orna- 
mented with rings, or encircling rows or bands of nodules, or 
crenulated bands. 
This gasteropod was supposed by Woopwarp to have first 
appeared during the period of the Inferior Oolite, and to have 
become extinct during that of the Chalk; but Moorz has 
described a minute shell (N. liassica) from the Marlstone of 
Ilminster, and Mr EH. Watrorp, F.G.S., has found the same 
species in the upper bed of the Middle Lias at Aston-le-Wall, 
near Banbury ; so that if the shell is correctly described as a 
Nerinea, the advent of the genus must have been much earlier 
than was formerly supposed; but I think it will be found, on 
examination, that the so-called N. liassica is not a Nerinea, but 
a Cerithium. 
The Nerinea is usually found in calcareous strata composed 
of fine muddy sediment, partaking more or less of the character 
of marly Limestone, and is associated with shallow water shells. 
Woopwarp has computed the number of species at 150. 
