78 
The square figure is from a piece of the Sussex marble 
taken from the ruins of Lewes Priory, and given me by 
G. A. Mantell, Esq.; it shows the more or less perfect sec- 
tion or distorted outline of the dark coloured shelly remains, 
filled with whiter confusedly crystallized Carbonate ef Lime : 
in the grey or brown ground are an immense number of 
minute bivalve shells, resembling those of bivalve Monoculi,* 
but now very properly distinguished from the genus 
Monoculus by Lamarck, under the name Cypris; the form 
of the shell is much like that of Mya ovalis: in another 
specimen I received some years ago from Mr. Weeks, there 
are also many small Vivipare, probably the young progeny 
of the larger shells suddenly arrested by fate. The four 
figures by the sides of the slab exhibit fragments detached 
from less compact pieces of the marble. 'The group below 
is from near Ashford, as before mentioned, the specimens are 
commonly only casts of the interior of the shel somewhat 
distorted; on either side are detached varieties. I have 
never seen the operculum of any fossil specimen. 
VIVIPARA extensa. 
TAB. XXXI.—Fig. 2. 
Spec. Cuar. Volutions four or five, subconvex, 
lower part rather angular, inner lip swelling a 
little at the umbilical side, outer lip extended 
outwards. Shell about twice the length of the 
aperture. 
C—O 
Smoorn, three-eighths of an inch long, rather thin. 
This little white specimen so much resembles Helix ten- 
taculata of Linn. that I can hardly pronounce it to be a 
* So common in stagnant water at the present day. 
