182 Mr R. Edmonds oh tJie Sand-hillocks 



has, for the most part, accumulated imperceptibly upon a 

 continuously growing vegetable surface, — the deposits during 

 a single storm being too slight to cover the herbage or to 

 check its growth, except occasionally, when they were suffi- 

 ciently copious to bury it etitirely ; yet not so deeply but that 

 the turf has soon reappeared, and the gradual accumulation 

 has proceeded as before. These occasional complete cover- 

 ings of the herbage may be inferred from the dark lines or 

 vegetable remains above noticed, and even in their absence 

 from the perfectly preserved land shells which are frequently 

 found more numerous in horizontal lines than in the sand 

 immediately above or below them ; for these lines, although 

 not dark, are like the former, most probably, sites of old ve- 

 getable surfaces whereon the inhabitants of the shells sub- 

 sisted. Generally, however, the shells ar^ not thus une- 

 qually distributed, but occur precisely as if the sand had 

 been gradually accumulating and burying them, without ever 

 completely covering the growing turf whereon the animals 

 were feeding or hybernating. 



A few months since, while examining some of the deep 

 cuttings ill the hillocks about a mile from the sea, I disco- 

 vered, at the depth of about 50 feet, imbedded in a uniform 

 mass of sand, a great number of small land shells, within a 

 space only half an inch thick and three inches square. The 

 shells were mingled with sand ; and as they consisted of not 

 less than ten different species, the space, probably, small as 

 it was, included several nests. 



From the perfect preservation of these shells, and from the 

 impossibility of their inhabitants finding subsistence on the 

 bare sands, I conclude that they, as well as the numerous 

 other l^nd-shells which occur in an entire state in the hil- 

 locks at all depths, must have been imbedded in situ — in con- 

 tact with vegetable surfaces, whose former existence, it ap- 

 pears therefore, is now generally indicated only by the exu- 

 viae of the animals which once pastured on them. 



The shells found in the small space above described, are 

 of the following species, in various stages of growth : — helix 

 virgata^ and pulchella ; zonites radiatulus ; zua lubrica ; buli- 

 mus acutiis ; pupa umbilicatai marginata^ a^d anglica ; vertigo 



