338 Proceedings of the Royal Physical Society. 



at Elie, and gives a list of some Molluscan shells he had 

 observed in the lowermost of the interbedded peats. I 

 thought at first that the deposit to which I am now to refer 

 was one of the interbedded peats described by Mr Brown. 

 Mr Bennie, who has examined it, informs me, however, that 

 it does not seem to have any connection with these peat beds, 

 and this is partly borne out by the difference of the contained 

 organic remains. The present deposit occurs close to Elie 

 railway station, and is very little below the present surface 

 of the land. It is therefore more accessible than the Kirk- 

 land marl, and for this reason a larger quantity of it has been 

 examined. The material of which it is composed is of a dark 

 brownish colour, and consists partly of decayed vegetable 

 tissue and partly of earthy matter. The remains observed in 

 it comprise the shells of land and fresh-water Mollusca, the 

 shells or tests of Ostracoda, the elytra and other remains of 

 Coleoptera, and seeds, spores, and stems of plants. In the 

 examination of a deposit such as this, considerable experience 

 is necessary, owing to the difficulty there is in determining 

 whether the organic remains are contemporaneous with the 

 deposit, or merely recent introductions ; and even the expe- 

 rienced student finds it no easy task to discriminate satisfac- 

 torily what is contemporaneous with the deposit from that 

 which is of more recent date. Of course, the older the 

 deposit, the less difficult it is to determine between old and 

 new. In most of the post-Tertiary deposits which are at or 

 near the surface, or which have been for a time exposed in 

 section, the greatest care is required in the examination of 

 the contained organic remains. The presence of such remains 

 as the shells of bivalve Mollusca and Ostracoda, if more or 

 less perfect, are not so likely to be misleading as some others, 

 because their habitat is a more localised one, and a very 

 little transportation has a tendency to separate the valves of 

 the dead shells of such organisms. 



In the following enumeration of species obtained from this 

 deposit at Elie, the greatest care has been taken to include 

 only such as appeared to be contemporaneous with it — several, 

 such as Helix hispida, Cocklicopa luhrica, and others being 

 excluded as doubtful. 



