XEROPHILA ITALA. 119 
bicuspid, and constituted by the mesocone and an ectocone; the marginals are 
about twenty in number, and also mostly bicuspid, but the ectocone gradually 
increases in Importance as the margin of the lingual membrane is approached until 
it almost equals the mesocone in size. 
The formula of the radula of a Chipstead specimen prepared and photographed 
by Dr. E. W. Bowell is 
20 pie pi4+ ir 45% x 120—= 7,800 teeth. 
Reproduction and Development.—Few observations on the modes 
of reproduction have been made, but it is probable that the male element 
is transferred during conjugation by means of a filiform and_ serrate 
spermatophore. 
Mr. Stubbs in the latter part of January, 1900, found a large colony on 
a sheltered sunny bank with a southern aspect, near Hertford, in active 
movement, and many of them in sexual conjunction, so that it 1s probable 
that in favourable seasons this act 1s continued more or less intermittently 
throughout the major portion of the year. 
The late Dr. IXobelt has affirmed from direct observation in his terrarium 
that only one love-dart is extruded and used during the amatory preludes 
leading up to conjugation. 
M. Bouchard Chantereaux records that .V. ¢ta/a lays its eggs from 
August to November; they are from 40-60 in number, agglomerated 
together in small clusters, and are about 12 mill. in diameter, of a spherical 
shape, and of a dull white colour, due to the numerous crystals of carbonate 
of lime in the envelope. 
Egg deposition has been frequently observed in Ireland by Mr. R. A. 
Phillips, both in the spring and autumn months, who remarks that the 
animal prepares a nidus by excavating a hole in the ground, about half- 
inch deep, and buries its body therein when depositing the eggs, which are 
probably afterwards covered with the earth. 
The eggs hatch in about three weeks, the young shells being said to be 
uniformly horn coloured, becoming gradually more opaque and banded as 
they increase in size, and are adult towards the middle of the following 
year, the bulk of them usually dying off during their second hibernation. 
Habits and Habitat.— \Vervphila itala 1s a very sluggish and timid 
creature, shrinking within its shell at the shghtest alarm. I[t is an emin- 
ently gregarious species, frequenting thistles, furze-bushes, ete., sunny and 
exposed grassy moorlands and pastures, or dry slopes and eminences. 
X. itala is most plentiful on chalk or limestone soils, especially on the 
dunes, cliffs, and barren slopes of our coasts, but is also found on sandy or 
clayey soils, as well as in old quarries, broken ground, etc. ‘The shell 
being more calcareous or more horny in accordance with the nature of the 
ground. ‘Though frequenting the driest localities, it has the habit, in 
common with Vheba cantiana and a few other species, of ejecting a 
comparatively large quantity of apparently pure water when roughly 
handled, and it is vouched for by Dr. Jeffreys and others that continued 
rains destroy great numbers of them. 
It is a subdominant, or is perhaps more correctly described as a con- 
ditionally dominant, species, which is more or less restricted to compara- 
tively inhospitable ground, and this apparent subdominancy is displayed 
at 'l'enby, Pembrokeshire, where Mr. A. G. Stubbs found that .Y. ¢tala was 
driven off when the occupied ground was invaded by HZ. pisana ; while 
