BEACHES, ETC., OF THE SOUTH OF ENGLAIfD. 



277 



Compton Bay (p. 237), which is 20 feet thick, that above Brixton, and 

 perhaps that on Gore Cliff [in which land-shells occur] (p. 238), as 

 well as some other beds, may likewise belong to the Eubble-drift, 

 but I have not had an opportunity of visiting the island since the 

 publication of that Memoir. 



(13) Isle of PurhecTc. — In the same way it is probable that the 

 Kaised Beach passed at a short distance from the present shore, at 

 the back of the Isle of Purbeck. Here again with the wear of the 

 coast, all traces of it and of the greater part of the Head have been 

 lost. In Encombe Park there is a trail of mixed gravel and brick- 

 earth, descending in a small shallow gully from the higher ground 

 above, and not connected with any river or valley-course ; like 

 the bed at Folkestone Battery, it most probably belongs to this 

 drift. At a height of about 240 feet, and half a mile from the edge 

 of the cliff, remains of the under-mentioned animals, which I saw in 

 the collection of the late Lord Eldon, were found : — Elephas primi- 

 genius, Jihinoceros tichorhinus, Cervus tarandus (?), Equus, and Bos. 



At Lulworth and Arrish' a Head of local drift descends to near 

 the shore-level, but the Beach is still absent. 



(14) The Isle of Portland.— The beach on the top of Portland Bill 

 is in an admirable state of preservation. The details of it will be 

 found in a former paper by the present writer,^ and the shells, which 

 are numerous, are tabulated with others at p. 300. The relation 

 of the Head to the Beach, and the very significant features of the 

 former, are best seen in a section near the top of the cliff west of 

 the lighthouses, at the southern end of the long inclined plane 

 forming the surface of the island. 



Fig. 6. — Section on the western side of Portland Bill. 



a. Rubble of angular fragments of Purbeck Beds. 



a'. Rubble (much contorted) of sand and marl, with numerous patches 



of land-shells and several large angular blocks of Purbeck strati. 

 c. Raised Beach (no shells in this part)— disturbed at its junction 



with the overlying Rubble. 



1. Purbeck strata. 



2. Portland rock. 



The Hubble-drift, a, a', which is here only from 5 to 15 feet thick, 

 is bent back, as it were, on itself, doubling over the Beach (fig. 6j. 



1 Quart. Journ. Geol. Soc. vol. xxxi. (1875) p. 29. 



