8 HYGROMIA STRIOLATA. 
abundance a decided preference for chalk or limestone ground, where it is 
generally plentiful; it is less so on sand, and especially on clay. — It is 
very fond of damp places, osier-beds, and ivy-covered walls or hedges, 
and is also found plentifully in gardens and in hedge-rows, amongst 
nettles, ete. On the sea-coast the largest shells often live or are found on 
bramble and sea-cabbage. 
Though usually geophilous in habit, it has been known to ascend trees 
and hedgerows to a good height, and to remain for hours adherent to the 
upper twigs, and even to wstivate on the boles of trees fuliy exposed to 
the sun’s rays. It also tends to inhabit more open country than, judging 
by its hirsute immature shells, was apparently the case at some former 
period, and is undergoing modification in adaptation thereto. 
It is nocturnal or crepuscular in habit, seldom stirring from its place of 
concealment during the day, unless in very moist and showery weather, but 
hiding in the crevices, or crawling beneath stones, heaps of rubbish, ete. 
It is a fairly active species, carrying its shell inclined to the right side 
and towards the front when crawling, and ranges to an altitude of about 
4,000 feet in the Alps. 
Like //elix cantiana, it voids when irritated or roughly handled a 
quantity of limpid tasteless fluid, but this feature is not so marked a 
characteristic as in Helicella virgata and its alles. 
Though AZ. striolata begins to retire for hibernation when the tempera- 
ture sinks to about 38 deg. Fahrenheit, often as early as October, yet it 
breaks its hibernation in the damp and milder days of winter, and wanders 
about and feeds when the temperature reaches 40 deg. Fahrenheit. 
The cireulation of this species shows considerable power, as at 31 deg. 
Fahrenheit it shows five or six heart contractions per minute, all very full 
and deliberate and not weak and feeble as in certain other species. 
The vertical lines connect the corresponding points of temperature and pulse rate. 
6 65" 
a 2 60° 
3] 557 7 53° 
324 3 —}50" 
ES == ee 
se | OE = S=== =" 
eS | 40 22S) Ss Se SSS Ss SS SS 
em sy it et Se 
| 3 SS SS = SS SS SSS 
Se 
x = — === = = SS SS SS 
ro) es Ge GE oe ee Ge es ees ee * 30 . 
ors 7 === 
a 2S 2a 2a 
= SSS SS SS SS SS SS ie 
ee | ——_ Oo oS 
3 — _— os 
<a = 
Z | = = = =F | 
: SS ye eS = 
Zz \ Sis 5 
Fic. 21.—Diagram illustrating the influence of temperature upon the pulsations of the heart of 
Hygromia strio/ata Pfr. 
Enemies.'l'he enemies of this species are those of the land mollusea 
generally. It is known to be devoured by rats. he thrushes are very 
fond of it, as is shown by the frequent presence of the broken shells at the 
thrush-stones; and the crops of the nestlings of the missel thrush (7Turdus 
viscivorus), wood pigeon (Columba palumbus), and stockdove (Columba 
wns) have been found to contain or be filled with the shells, while even 
well fed fowls pick up and eat those creatures with evident pleasure. 
‘ayeos ayuaiyeg 
‘aduri [RULIaY YT, 
aanutu iad 
Suonesind jo saquiny 
