236 POPULAR BRITISH CONCHOLOGY. 



bears a small^ flat, oval, more or less rudimentary shell 

 under its shield. 



LiMAX cmereus is a larger and finer species, sometimes 

 growing to the length of six inches. Its head is pinkish- 

 grey, and the body and shield striped, and mottled with 

 ash-colour; the back of the tail is keeled, and the shell 

 under the shield rather large, and of an oblong square. 



LiMAX arhorum lives on trees, eating the wood, particu- 

 larly in the decayed parts. It mounts the branches, and 

 has the power of letting himself down by means of a thread 

 of mucus, like that of a spider. 



LiMAX fiaviis is the large fleshy slug w^hich leaves its 

 slimy trail on the walls of cellars and damp places under 

 ground. 



The remaining species are L. g agates and L. Soioerhn, 

 which have keeled backs; the small L. hnmneus and the 

 rare L. tenelliis. 



Family TESTACELLID^. 



Testacella HaUotoidea may well be placed in a separate 

 family from the Limacince, although very slug-like in its 

 form and appearance. It is intermediate between the slugs 

 and the snails, carrying a small ear-shaped subspiral shell 



