Correspondence. 377 



Sponges. And this is precisely what we might expect in so ancient 

 a form. For it is well known that the more ancient forms often 

 blend the characteristics of types, or as Dana expresses it, they are 

 " comprehensive types." In this way Eozoon may, to some extent, 

 comprehend the characters of BMzopoda and Spongiadce. Without 

 committing myself, however, to all the generalizations, frequently 

 extremely hazardous, of the celebrated American geologist, I may 

 remark that all this is perfectly compatible with the doctrine of 

 descent with modification, and that that hypothesis is the only one 

 yet propounded which satisfactorily explains these alliances. 



I find myself completely borne out in my views on the nature of 

 Eozoon by the discovery by Principal Dawson of siliceous spicules in 

 the cells of that organism. It is true, that able paleeontologist attri- 

 butes these spicules to a sponge which has fiUed the cells of Eozoon 

 subsequently to the death of the latter. But I think, in view of the 

 resemblance between the structui-e of Eozoon and that of the boring 

 sponges, that the hypothesis of Dr. Dawson is wholly unnecessary, 

 and that there is no difficulty in attributing the' spicules to the Eozoon 

 itself. — I am. Sir, your obedient servant, 



E. LeOHMERE GrUPPY, 

 Port-of-Spatn, Trinidad, 

 3rd June, 1867. 



SHELLS ON THE GREAT ORMESHEAD. 



To the Editor of the Geological Magazine. 



Deab Sir, — In the paper on " Glacial Action near Llandudno," in 

 the July number of the Magazine, Mr. Bonney (page 290) notices 

 the occurrence, in the surface deposit at Gwydfyd, on the Great 

 Ormeshead, of quantities of shells. It is worthy of remark that 

 there are none but those of eatable species, — Patella vulgata, Littorina 

 littorea, Mytilus edidis, Ostrea, and Tapes. I obtained examples here 

 in November, 1864, when their extreme profusion, and the way in 

 which they occurred, convinced me that they had been brought there 

 by the hand of man. I find from a section I made at the time, from 

 the pier at Llandudno to the top of the Ormeshead, that the shell 

 bed occurred at a height of 380 feet above the sea. The accumula- 

 tions of the subaerial loam which covers it would seem to imply 

 very great antiquity in relation to the human period ; but it is evi- 

 dently quite a different deposit to the Boulder-clay that occurs on 

 the coast at the bottom of the valley, here limited to a range of about 

 170 feet above the sea (it terminates close to the lowest fence). 



Similar clay with transported boulders forms a terrace of about 

 the same height on the south side of the Head, and attains a some- 

 what greater elevation on the flanks of the Little Ormeshead. 



Whilst suggesting that the Gwydfyd shell-bed is of artificial 

 origin, I do not wish to call in question the evidence Mr. Bonney 

 brings forward in proof of Glacial action, as drift with transported 

 and striated boulders is abundant in the neighbourhood, especially 

 on the east side of Orme's Bay. There is also a good section con- 



