30 
SPIRE, BASE, ETC., IN UNIVALVES. 
the columella but also the shelly partitions separating the coils of 
the body, so that in extreme cases the interior 
of the .shell forms one simple cavity only, owing 
to this absorption of its internal divisions. 
Other species, as Cdrillolde.'^ acicnJa, I'extdci'lhi 
sciitii/iim, etc., have the columella truncate 
at its base ; this peculiarity has been held to Fio.oT—Univaivewiti. 
indicate carnivorous propensities in the species 
1 ‘i-'i* * 1 - liishopswood, Ross, Here- 
6XlllOltlU;^ it. fordshire, collected by 
Rev. R. W. J. Smart, M.A. 
P'lG. 58. — Univalve F'lO. 59. — Univalve with 
with Klongate Spire. Depre.ssed Spire. 
L. f^lab a (Miiller), P. corncus albina Mo(j., 
Twenty Pits, Mill Pond, KifT«)rd, 
near Manchester, near Ring’s Norton, 
Coll, by Mr. J. R. Hardy. Warwickshire, 
Coll, by Mr. J. Madison. 
The Spire includes the 
whole shell, with the excep- 
tion of the last or body 
whorl, and is very varied in 
the character and disposi- 
tion of its coiling. It may 
be di.scoidal or Hat, as in 
Phtnorhis, or greatly elon- 
gated as in Limmrd (jidhrd. 
The Apex or nucleus of the shell originates 
in the ovum, and is the first and smallest 
whorl, and in some genera has great signifi- 
cance, being differently formed from the rest 
of the shell. In the 
JMk elongately coiled .species 
% 
Kit,. 00. 
pi . , . , Univalve with Ape.x J’erfect. 
llKG ij. the Li/una'a palustris Mull., 
. Maidenhead, Herks., 
tip IS lltlble to erosion ColI. by Mr. C. G. Harrelt. 
and loss, the shell thus becoming decollate; 
the discoidal freslnvater shells are not exempt 
from this injury, the Plduorhes being found 
Kig. G1. 
A Decollate Univalve. 
Limnwa pahistris Miiller 
u\. (iecollatum JefTr., j. /* 
Quarry, Christleton Rd.Che.ster, liot Ullire(|lieiltl V pGl lOnitcd tlirOU^(ll tllC CClltl’e 
Coll, by Rev. H. Glanville . ® 
liarnade, M.A. Oil aCCOUllt of tlllS 61*0- 
sion and lo.ss of the earlier and smaller whorls. 
The Base of the shell is the o])j)osite 
extremity to the apex ; it is the anterior 
end and is the last formed jiart of the .shell. 
The Periphery is that portion of each 
whorl which is the most outwardly produced 
Pic;. G2. 
Hasal aspect of an Univalve 
(slightly enlarged). 
Helix hortensis Muller, 
Fordingbridge, Hants., 
Coll.byMr.H. Richardson M.A. 
