ARION SUBFUSCUS. 197 
Mr. Gain found that of 130 different kinds of food tendered to them 
while in confinement only one, the Violet (Viola odorata) was eaten with 
avidity, although forty-six other kinds were eaten freely, forty less readily, 
and only forty- three were totally rejected. 
This species frequents both deciduous and pine forests, and ascends the 
mountains to the limit of trees, but it also lives in gardens at the foot of 
walls and rocks, under hedges bordering meadows or roads and other places. 
It is fairly plentiful on the London clay, in gardens, ete., in North London, 
but is often especially abundant, fine and richly coloured on or near refuse- 
heaps. Like its congeners, it is somewhat slow, timid, and clumsy, though 
more active than A. ater, but when young or partly grown is a great adept 
at spinning mucus threads, and has been known to spin a thread thirty- 
seven inches in length. It is one of the few species of slug which has been 
actually observed and recorded as able to reascend its ‘thread. This is 
effected by curving the anterior part of the body upwards until the fore- 
part of the foot comes into contact with the hinder portion, up which the 
creature then crawls until thé thread is reached, the animal then applies 
its foot to the thread, and at once proceeds to ascend by its aid, the 
foot remaining nearly flat or only shghtly folded in front. During the 
operation the head is moved from side to side and mucus gradually aceu- 
mulates in an irregular mass above the tail, evidently composed in part of 
the slack of the thread, as it could be to some extent unwound or disen- 
tangled from the mass. 
Parasites and Enemies.—'he general enemies of the slugs also 
prey upon this species, but, according to Mr. L. E. Adams, poultry which 
refuse Arion ater will eat this species without hesitation. Numerous 
intestinal worms have been at times detected within this slug, but they 
have never been identified. 
Variation.—This species does not display that wealth of colour- 
variation shown by Avion ater, the variations being chiefly due to the 
greater or lesser intensity of the rufous tint, and the more or less complete 
overspreading of the body by the darker hue of the dorsal surface ; this 
Fic. 216. Fic. “OT. Fic. 218. 
Proximal ends of the Reproductive Organs of Avion lusitanicus and A, nobret. 
Fic. 216.—A77on lusitanicus (after Pollonera). Fic. 217.—Avrion lusttanicus (after Simroth). 
Fic. 218.—Avion nobrei (after Pollonera). 
distribution of colouring is, however, liable to be rev ersed, a variety found 
on the Serra d’Estrella ‘having the dorsum clear brown, while the ‘sides of 
