OSSIFEROUS CAVES OF GOWER. 501 



partially examined by Sir H. de la Beche, and thoroughly 

 explored by Colonel Wood in 1849. Although but of con- 

 tracted dimensions, it has yielded a very large quantity of 

 fossil bones, belonging to many genera and species. 



5. ' Mewslade Bay.' — Eaised Beach observed by 



Prestwich. 



Before proceeding to notice the contents of these caves, it 

 will be convenient to refer to the highly valuable observation 

 made by Mr. Prestwich upon the raised beach of Mewslade 

 Bay, when he and I visited Gower last autumn. A thin 

 layer of marine sand, containing shells of common existing 

 species, was observed by Mr. Starling Benson and Colonel 

 Wood, at the bottom of the deposits in ' Bacon Hole ' cavern ; 

 and marine deposits of sand and gravel are common on the 

 floors of some of the other Gower caves, as will be shown in 

 the sequel. It was of importance to place these beds, either 

 in correlation with, or distinction from, some definite patch 

 of raised beach in the neighbourhood. Mr. Prestwich dis- 

 covered in Mewslade Bay, between Paviland and the Worm's 

 Head, the well-marked illustration of this nature, repre- 

 sented by the accompanying section, for which I am indebted 

 to his kindness (p. 537) . At ten or twelve feet above the level of 

 high tides there is perched upon the weathered outcropping 

 edges of the limestone a narrow belt of raised beach, a mile 

 in extent. The section shows a bed 3 feet thick, composed 

 of fragments and pebbles of limestone, with entire and broken 

 shells, imperfectly cemented by a calcareous paste. Above 

 this there is a bed of reddish sand, 4 feet thick ; and the 

 whole is overlaid by an enormous mass, varying from 20 to 

 30 feet in thickness, of angular fragments of carboniferous 

 limestone, being the debris of the immediately adjoining 

 rocks. This bed is developed in vast accumulations, at a 

 considerably higher level, on the face of the cliffs between 

 ' Bacon Hole ' and ' Minchin Hole,' and it constitutes a well- 

 marked example of ' Breche en place,' or the bed which 

 Mr. Godwin- Austen has characterized, in his memoir on the 

 ' Pleistocene Period,' under the designation of ' Head.' l 

 Mr. Prestwich's remarks on the traces of ' Boulder Clay ' in 

 Gower will be found in his notes in the appendix. 



6. ' Bacon Hole ' Cavern. 



Description. — The cavern of ' Bacon Hole ' may, with 

 advantage, be taken first, as it was very carefully explored, 

 under the constant superintendence of Colonel Wood ; and an 



1 Quarterly Journal Geol. Soc, vol. vii. (1851), p. 121. 



