ScHARFF — The Slugs of Ireland. 195 



of the mantle, as in Avion. Instead of the large triangular 

 caudal gland which characterizes the species of Arion, it has only a 

 transverse slit at the end of the body. 



All the species of Limax and Agriolimax have a very wide 

 distribution, ranging almost throughout Europe. The two species 

 of Anialia have a less wide distribution, being more or less confined 

 to Southern Europe. The exact range of the species of Arion is 

 not so well known, but Arion ater seems to be spread over the 

 greater part of Europe, and while A. subfusciis and A. Bourguignati 

 are found in the north, A. horfensis is confined to Central and 

 Southern Europe. 



The colouring of slugs seems to be on the whole strictly pro- 

 tective, the most striking example of protective colouring among 

 them being found in Limax marginatum, Arion intermedius, and 

 Geomalacus maculosus. The first resem,bles the bark of the trees 

 among which it lives ; the second, a fungus-feeder, is just like a 

 little mushroom emerging from the ground ; while the last is so 

 much like the lichens on which it lives, that it is very difficult 

 to distinguish it from its surroundings. 



SCIEN. PROC. R.D.S. VOL. VII. PART III. 



