DEPOSITS AND ELEVATION. 17 



the wave- worn hollow. On the south-eastern inland cliff, 

 the wave-marks seem to have suffered considerable dis- 

 location, as if this part of the hill had undergone a more 

 violent elevation. 



V. Distinct remains of raised beach are to be seen at a 

 spot on the east side of the Head, near the bath-house, 

 where masses of shingle hang cemented to the face of the 

 rock, at a height of about 50 feet above the sea-level. 



vi. Lastly, there lies upon the boulder-clay of the 

 isthmus, and especially developed and visible in the cliff- 

 section of the western shore, a deposit, varying in thickness 

 at different points along this line, from a few inches to 3 

 or 4 yards, of coarser or finer beach-shingle, sometimes 

 mixed with a little clayey material. The bed is seen at a 

 lower level in foundations in Mostyn Street (where it yields 

 abundance of mussel-shells, double, as if dead in loco), and 

 may be continuous with the present beach- shingles of 

 Llandudno Bay. Its constituent pebbles are not dis- 

 similar to those of the recent beach, though there often 

 seems to be a somewhat larger proportion of stones from 

 granite, Silurian, or trap beds. The beach itself is now 

 chiefly supplied from the limestone heads at each end 

 of it, or one of them. 



vii. Over this beach-shingle lies, in many places, more 

 or less of drift sand. I have heard it stated by Mr. Thomas 

 Glover (who has been familiar with the locality and with 

 such observations for fifty years past) that within his own 

 recollection a large expanse of low ground was, forty or 

 fifty years ago, an impassable swamp, and has since been 

 converted into solid ground by this drift sand, and is now 

 overlain by, it. 



b. Pholas -burrows. 



viii. I have reserved for a separate section, in order to 

 present this series of facts together, another class of un- 



SER. III. VOL. IV. c 



