——— 
a74 HELIX PISANA 
This local and possibly atavistic forn’ is more common in Portugal than 
in France, where it is known to oceur at Palavas, Hérault ; Port Vendres, 
Pyrénées Orientales ; and also at Catalans, and Chateau d’If near Mar- 
seilles. In Portugal, it is found at Lisbon, Monsante, Alcolena, Evora, 
and Lega. In Morocco, at Mogador, 'Tetuan, and plentifully at Melilla 
and Tangiers; and in Algeria, exists about the vicinity of La Macta 
and Arzen, and is common in many places on the coast. 
On awakening from its summer siesta, after the first rains, at the end 
of autumn, the ‘orowth is renewed and takes place more rapidly, the new 
growth differing remarkably by its pigmentation and delicacy from the 
earlier portion, Dut the shell is gradually thickened before maturity, which 
is attained in the following spring, about eighteen months after birth, but 
extending over portions of three years. 
In England, the shells become full grown about July, but our summers 
are seldom sufficiently prolonged to allow of the lip being ‘perfectly developed, 
and few mature individuals would appear to survive their first hybernation, 
as only a very limited number of living adults can be found in spring, 
though hundreds of dead ones strew the ground, and the young are active 
and abundant. 
Habits and Habitats.—/. pisuna is most plentiful in dry and and 
regions, especially within the influence of the sea; it lives and prospers 
under a variety of conditions, 
dry sandy plains, in gar- 
dens and fields, by roadsides, 
in hedges and on hill slopes, 
usually adhering in great pro- 
fusion to thistles and other 
plants, the trunks and stems 
of trees and bushes, and on 
walls, usually in places fully 
exposed to the sun, the ani- 
mal having a wonderful capa- 
city for enduring solar heat. 
Though in hot weather they 
do not seek the shade, gener- 
ally living during the day 
attached to the vegetation or 
other support by a strong epi- 
phragm, yet they occasionally 
during long continued drought, 
as observed at St. Ives, Corn- 
wall, bury themselves some 
inches deep in the sand at the 
roots of Carer arenaria or 
other plants, but the young 4 
are stated to invariably select [Ria 
and remain fixed in positions Fic. 421.--Helix pisana congregated on its food plant 
fully exposed to the sun. at Tenby (from photograph by Mr. C. H. Moore). 
At Tenby, even in winter, according to the observations of Mr. Stubbs, 
the adults whoa hibernating do not seek shelter from the cold by burrow- 
ing or by hiding in suitable crevices, but still continue to cling to the dead 
stems of the herbaceous plants upon which they feed in summer, and are 
mostly destroyed by the trying conditions to which they are exposed. 
