HABITS AND FACULTIES. I93 



timber, to the lower surface and crevices of which they 

 adhere by a mucous attachment during the day, in hol- 

 lows under the roots of trees, and under the layer of 

 decaying leaves which cover the ground. In situations 

 where such places of shelter are not found, they half 

 bury themselves in the soil, at the roots and under the 

 shade of thick tufts of plants. Numbers frequently 

 resort to the same retreat, but this in the Helieidce seems 

 a mere matter of accident, while in the introduced 

 species of Limacidce it appears to indicate a gregarious 

 habit, as they prefer to crowd together and lie in close 

 contact with and upon each other.^ These last are said 

 by some to occupy permanently the same retreat, but 

 the assertion is probably incorrect. They often, and 

 perhaps generally, remain in the immediate vicinity of 

 the place where they procure their food, and hence they 

 often resort to the same place of shelter ; and as many 

 of them have frequently been observed in the same 

 place, they have been thought to be the same individuals. 

 But when one set of individuals is destroyed another soon 

 takes their place, and whenever a new shelter is provid- 

 ed, by the accidental presence of fragments of wood in 

 suitable situations, it is immediately resorted to by them. 

 The native genus Tebennophorus is in no manner grega- 

 rious ; it lives in the forest, mostly buried in decaying 

 and rotten wood, and no more than two are usually found 



' The promiscuous mingling of individuals of Limaz agrestis and Limax 

 variegatus in their respective retreats has often reminded us of the familiar 

 positions in which swine place themselves for sleep. 

 VOL. I. 24 



