ARION. 23 
where else?) and he instances a beautiful example of 
protective mimicry in the case of Geomalacus maculosus. 
The results of my own collecting tend to show that 
climate may be a factor in the matter. 
Dealing first with inland localities, I find that I have 
taken more brilliant forms and those more abundantly in 
the south of England (where the climate ts warmer) than 
in the north. In the northern counties I have very rarely 
taken adult specimens other than the type; in the 
Midlands coloured varieties only occasionally appear, 
while the southern and western counties often teem with 
coloured forms-—the type sometimes being a rarity. 
Secondly, dealing with coast localities—all along the 
south coasts of England and Wales, Cardigan Bay, and 
the west coast of the Isle of Man and the north coast of 
Ireland (all of which are noted for a mild climate) I have 
taken coloured forms abundantly ; while on the coasts of 
Lancashire and North Wales and the east coast of 
England from the Thames to the Tees (zhere the climate 
ts more bracing) I have no personal records for anything 
but the type. 
But before we can generalize confidently we require a 
vastly greater amount of observations. 
To identify this species it is only necessary to irritate it, 
when it will contract into a completely hemispherical 
lump. With the exception of A7ton minimus, this is the 
only member of the genus that can assume this shape, 
and it very rarely has any traces of banding. 
