BEESTON : KIK.LO NOTKS ON HELICODONTA 0)!VOI.UTA. 47 



Miss Hele that the animals do not feed on moss. Three (perhaps 

 four) sul)stances provide them with food, viz. : — minute Hchens, 

 mycetozoa, fungi, and probably mycehum. They may also in very 

 dry weather feed on damp and macerated beech leaves, as I often 

 find tiie snails clinging to these leaves on dry hot summer days. 



In early spring, the snails immediately on leaving their hibernaculum 

 climb the beech trunks for a few feet. This, I believe, is for the pur- 

 pose of feeding on the small, soft lichens above the point where 

 mosses cease to grow on the boles of the trees. On reaching the 

 lichen zone, they travel no higher, and after feeding either remain 

 quiescent or descend again. 



After the heat of summer is over, they probably return for another 

 feed on the lichens, when the plants are moist, once again returning 

 to earth for the remainder of the year. It is this descent after feeding 

 in autumn that no doubt has led to the idea that the snails were 

 descending from the branches after spending the summer there. 



Personally I have not observed this autumn feeding, but several 

 other species do likewise in search of special food. With regard to 

 the mycetozoa, I have ample proof, having many times found the 

 snail in considerable numbers on decaying timber, on the underside 

 of which, in close contact with the leaves and earth, the soft slimy 

 mass grew abundantly. 



Close observation showed that mastication was in progress, possibly 

 attended by slow absorption of the sticky mucilage. Chemical 

 analysis of the mycetozoa has shown that carbonate of lime is an 

 important constituent. These molluscs are also extremely fond of 

 other fungi, particularly Boletus ediilis, but only when it has arrived 

 at the deliquescent stage of decay. Once, in Nov., 19 13, I discovered 

 nine specimens beneath a Boletus, the stem of which had collapsed 

 and let down the pileus flat on the ground ; one of the molluscs 

 was partly buried in the decayed flesh of the cap. Although several 

 other kinds of fungi are to be found in the woods, I have not suc- 

 ceeded in finding H. obvoluta feeding on them. 



jSIycelium also, I believe, forms part of their diet, as on several 

 occasions I have found the snails clinging to the network of myceloid 

 growth on partly-buried, half-rotten timber, and owing to the absence 

 of mycetozoa or lichens on the wood, I presumed they were using 

 this as food. 



Geological Distribution in England.— 



There seems very little information on this point. Mr. E. W. 

 Swanton states : — "The Rev. W. A. Shaw found it in a post-Pliocene 

 deposit at Kingley Vale, near Chichester." 



