70 ARIONID^. 



variety, sometimes form an irregular sub-hemisphe- 

 rical spongy shell. 



It has a great geographical range, being found 

 equally in Ireland and Norway, and Italy and Spain. 

 It deposits its bluish eggs in a cluster, in May, 

 at the roots of plants. 



It feeds on dead and living vegetables, and some- 

 times, according to Mr. PoAver {Linn. Trans, ix. 

 323.), on dead earth-worms. 



The country people consider the appearance of 

 this slug as an indication of approaching rain ; but 

 this is rather to be accounted for by the moisture of 

 the ground and of the plants. It is seldom, indeed, 

 to be observed abroad during dry weather, for this 

 would deprive the body of the moisture which is 

 requisite for its existence, {Bingley.^ 



A black slug {Arion ater), placed in a box of 

 sand taken fresh from the sea, after emitting a 

 quantity of mucus, became reconciled to his situa- 

 tion, and commenced eating the sand to extract the 

 organic matter. The faeces were at first of a green 

 vegetable colour, but were at length entirely com- 

 posed of pure sand, the grains united together into 

 their usual form by a little mucus. {Gray, Ann. 

 and Mag. N. H. ii. 310. 1829.) 



b. Shell imperfect, rugose, rarely wanting. (Prolepis.) 



14. 2. Ariox hortensis. Garden Arion. — Black, 

 with grey longitudinal streaks ; edge of the foot 

 orange ; shell imperfect, rugose, or wanting, 

 (t. I. f. 16.) 



