30 



THE YOUNG NATURALIST. 



1. Body greenish- white, mantle yellowish, glossy and nearly transparent. 



2. Head and tentacles black ; the tentacles are sometimes marked with a 

 faintly visible whitish streak on each side. 



3. Mantle wrinkled concentrically. 



4. Slime yellowish. 



5. Shell oval, moderately solid, and having a membranaceous margin. 



The first specimen of this slug was taken near Allansford, in Northumber- 

 land, by Mr. Blacklock. No varieties have been recorded as British, and 

 indeed, tenellus does not seem to undergo such variation as the other members 

 of its group. Two very pretty foreign varieties occur, one is orange- green 

 in colour (v. xanthia) and inhabits Germany, the other is Lusitanian and has 

 its body colour of a golden green (v. squammatina), 



L. Arborum. — -This is the tree-slug, and of all trees perhaps the one tree 

 which it has the most prediliction for is the beech. You can see it sometimes, 

 if you are a careful watcher, hanging down from one of the branches of these 

 trees, by a thread which it has wrought out of its own mucus, and dangling 

 first to this side and then to that. It is a pretty slug, and when once seen 

 will not be forgotten in a short time. Tabulating its specific characteristics 

 we get the following : — 



1. Animal greenish or slaty-grey coloured with yellowish- white spots, and 

 a dusky band on each side. 



2. Mantle rounded in front, ending in an obtusely cut point behind, and 

 concentrically wrinkled ; tentacles short. 



3. Foot with a white margin. 



4. Back somewhat keeled towards the tail. 



5. Slime colourless and sticky. 



6. Shell (under the mantle) all but oval, very thin, flat, glossy with a 

 broad and membranaceous margin. Nucleus nearly terminal. 



A variety which was described by Sordelli as inhabiting Italy has been 

 found to belong to our own country also. This observer named it var. 

 Beltonii, and a translation of his description runs thus : Animal ornamented 

 on the back with white and fuscous spots ; median band white, with two 

 accompanying fuscous bands ; median band on mantle white, with two alter- 

 nating white and fuscous bands : keel short. Mr. Roebuck has also described 

 a variety as var. maculata which is as yet not recorded from any continental 

 locality. The markings in this are reduced to small and sharply defined 

 black spots, and has a thin continuous band running along each side which 

 shows a tendency to break up into spots. 



L. arborum is local but pretty freely distributed nevertheless. 



