bE 
ORTHOCERA annulata. 
TAB. CXXXIII. 
Spec. Cuar. Slightly tapering, gently compressed, 
with strong annular undulations, and minute 
transverse undulating striz. 
Tue undulations are slightly oblique, ata distance equal 
to about one-fourth the diameter from each other; about the 
aperture which is oval, there is a considerable space without 
a ring: the siphuncle is placed a little way within the 
broader side of the shell. 
From a Limestone quarry at Colebrook Dale, Shrop- 
shire, it was presented to me by the friendly J. Cotton, 
esq. Lady Aylesford shewed me, some time since, 
a similar, but rather shorter specimen. It appears 
to taper so gradually, that we may suppose it 18 inches 
or more long when perfect. The upper part of the figure 
expresses the last chamber, which appears to extend 
three-fourths of an inch beyond the preceding septum. 
The form of the shell remains, it being replaced by Car- 
bonate of Iron, thin, but distinct, thickest at the annula- 
tions, which are occasionally dark brown from having been 
worn when uncovered, or destitute of the buff Limestone. 
The specimen is rather weighty, as if much impregnated 
with Lron. 
VOL..Ui./9/6. XXIV 
