336 PKOP. J. PEESTWICH ON THE EAISED 



vertical openings communicating with the surface, in several adjacent 

 limestone districts are also described by him. There was one at 

 Brixham 27 feet high, in which bones of Cave animals were extremely 

 abundant and in excellent preservation. Another in Warren Eoad, 

 Torquay, was 140 feet high, measured along its inclination of 

 40° E.S.E. Others traverse Daddy's Plain and the hills between 

 Anstey's Cove and Babbacombe. As it is generally in quarrying 

 that these fissures are discovered, it is obvious that many must escape 

 notice. 



The angularity and local character of the rock-fragments com- 

 posing the breccia, the broken and splintered condition of the bones, 

 the sharpness of their fractured edges, their frequent fresh state, 

 and the absence of wear or traces of gnawing, show the close 

 analogy between the Rubble-drift or Head and the Ossiferous Breccia, 

 and indicate a similarity of origin. The occasional ' sorting ' of the 

 deposits spoken of by Buckland, and the " occasional pauses or periods 

 of causation " of Mr. Pengelly, exactly tally with the successive 

 additions to the Elephant Bed of Brighton, as a result of intermittent 

 uplifts, and, consequently, of intermittent displacement and trans- 

 port of the surface-debris, — in the one case over the old cliff-edge, 

 and in the other into the open fissures. 



There is further stratigraphical evidence on the coast of Gower, 

 where there are both ordinary caves and fissure-caves. Speaking 

 of these Caves, Dr. Ealconer remarks on the presence of the angular 

 detritus " to which Mr. Godwin-Austen has applied the name of 

 'Head' . . . sometimes in vast accumulations in the immediate 

 vicinity of the Caves," and at other times intruding, so to speak, into 

 the interior of the fissures and Caves, where it occurs " cemented 

 by stalagmite, overlying the marine sands and stretching seaward 

 upon the face of the cliffs." Describing Bosco's Den, he says that 

 this detritus was there 6 to 14 feet in thickness, and the materials 

 corresponded in general character with the bed of angular debris 

 observed on the Raised Beach of Mewslade Bay. ^ 



Although, owing to the seaward dip of the rock, there is no thick 

 lodgment of Head on the beach, large sheets of it lie in places on 

 the slopes of the limestone, often masking both beach and caves, 

 and choking the fissures. The limestone plateau above the caves 

 is covered with a red clay and angular fragments of limestone, and 

 it is from this that the materials of the Head have been chiefly 

 derived. (See fig. 11.) 



I cannot, however, accept the explanation of the origin of the Ossi- 

 ferous Breccia suggested by Buckland and adopted with some modifi- 

 cation by DelaBeche, — an explanation which is still generally current. 

 They were of opinion that fissures which long remained open were 

 formed in the limestone by earthquake-movements. Into these the 

 animals which ranged the country fell from time to time, or were 

 driven in when chased by beasts of prey ; while fragments of the 

 limestone-rock dropping from the sides of the fissures, with the clay 

 and sand washed in by the rain and streams, gradually filled these 

 ^ * Palasontol. Memoirs,' vol. ii. pp. 517, 533. 



