420 ANIMAL REMAINS FOUND AT CISSBURY. 



and was conformable with the sides of the ditch. The sudden and 

 somewhat unexpected breaking through of this brittle flooring of 

 red silt and the opening into the shaft beneath, out of which a 

 large part of the skeleton had been extracted previously to my 

 coming, by Colonel Lane Fox and Mr. Park Harrison, was a 

 circumstance which, not only by virtue of its general sensational 

 character, but also by forcing upon me the fact of the finely par- 

 ticulate, and therefore the rain-washed character of the red seam, 

 made a great impression upon me. The red seam appeared, as it 

 were, to assert its claim to belong to the lower strata by the abrupt 

 manner in which it broke away, much as one geological stratum 

 parts in an escarpment from one above it. As many of the snails 

 below the seam were in large quantity, as well as individually of 

 large size, it was a matter of ocular demonstration that they had in 

 one way or another got down into the pit before the formation of 

 the red seam of the ditch, and of the ramparts. The length of 

 the galleries connecting shaft E with shaft H (fig. i, PI. xv.) 

 rendered it impossible to think that the snails could have found 

 their way into shaft H, as Colonel Lane Fox had done, by way of 

 those galleries, and there seemed then, as there seems now, to be no 

 escape from the conclusion that the ditch was a later, the shaft an 

 earlier, excavation. The mollusca, however, furnished us with a 

 stronger argument still. For the shells of the Oyclostomata had, in a 

 very great number of cases, their ojjercula still in relation with them. 

 This shows beyond all possibility of doubt that the animals had 

 crawled down alive, and had not simply worked down as dead shells, 

 a view which was further rendered untenable by the fact that in a 

 great number of instances the shells, both of the Cyclostomata 

 and the Helias, were adherent to the sides of the shaft. But they 

 would not have crawled down in rubble to the depths at which we 

 found them for any purposes of hibernation, nor could they, I think, 

 have worked their way through the red seam so often referred to. 

 On the other hand, the protection against both cold and drought 

 which an open shaft only 4 feet 6 inches in diameter and more 

 than three times those dimensions in depth, would offer to snails 

 on a chalk down, very fully explains both their presence and their 

 abundance. This latter point, viz. the great number of these snail- 

 shells, and especially of the Cyclostomata, found in the rubble-filled 

 shaft below t though not above, the red seam, calls for some consider- 



