DEPOSITS AND ELEVATION. 27 



it is probable that their original deposit on the Head is of 

 very ancient date. I may mention that once when I was 

 collecting specimens, an old Welchman remarked that 

 " Irishmen eat them/' 



There are on the central plateau certain traces of 

 foundations, which the same man pointed out to me as 

 Irishmen's houses. I have no means of fixing a meaning 

 or a date to these references. They may represent either 

 a comparatively modern, or, under vague disguise, an 

 ancient tradition. The fact of the occupation of the Head 

 for mining-purposes in very early times is well established. 



It is by no means impossible that a close search or a 

 fortunate accident might discover some cave of ancient 

 habitation in the valley of the old road. If the oppor- 

 tunity should occur, it should if possible be fully and 

 carefully made use of by competent observers. Some 

 years ago a skeleton of a man was found in a stalactitic 

 deposit in a cave on the western face of the Head; but 

 I think it was not shown to be of special antiquity. 



xiii. Before I pass on to the undisturbed deposits of 

 human origin, I may, in order to complete this sketch of 

 the superficial formations of the Head, mention a small 

 patch of shells which I found water-worn into a crevice on 

 the Western Clifi^. After washing off the clay matrix, 

 there remained, along with some bones of a frog, shells 

 of the following species : — Zonites cellarius and crystallinus, 

 Helix aspersa, nemoralis, caperata, rotundata, and pul- 

 chella, Pupa umbilicata, Clausilia rugosa, Carychium mini- 

 mum, and Cyclostoma elegans, comprising, I believe, all 

 the terrestrial mollusca of the Head except Helix virgata, 

 ericetorum and rupestris, Bulimus acutus, and two or 

 three slugs. 



III. Refuse-heaps and other Relics of Human Habitation. 

 xiv, Mr. Bonney's bed of shells at Gwydfyd pit has 



