198 PROCEEDINGS or THE GEOLOGICAL SOCIETY. [Mar. 20, 



Professor Phillips, and the Portland stone below. In a visit I lately 

 paid to that well-known locality for Portland fossils, I saw there several 

 masses lying about of a close-grained, concretionary, drab-coloured 

 limestone, very different lithologically from the Portland Oolite, 

 which attracted my attention. The average thickness of the blocks 

 was from six to eight inches ; and on the upper surface, which was 

 coarser and somewhat sandy, I detected Cypris and abundance of 

 fish-bones and scales, including two entire fish -jaws vrith teeth ; but 

 I could not find any shells. The aspect of this limestone was so 

 decidedly that of a freshwater deposit, and so similar to certain of 

 the Purbeck strata which I have studied in "Wilts and Dorset, that, 

 without having discovered a single fossil, I should have felt satisfied 

 that it was not of marine origin and was quite distinct from the 

 Portland Oolite. It has a very irregular, splintery, and uneven frac- 

 ture, and resembles the '' cap " of the Island of Portland, to which no 

 doubt it may be referred, and forms a reduced equivalent. It seems 

 also to resemble the lower and harder portion of the " pendle " at one 

 of the pits at "Whitchurch, described by Dr. Pitton *, which contains 

 bones and scales of fish. 



The stone had evidently been procured from the base of the estua- 

 rine sands, though, unfortunately, the excavation had been so filled 

 up that it was impossible to detect this undoubted remnant of the 

 Purbeck formation in situ. However much reduced in bulk these 

 freshwater strata are in tbis direction, it is interesting to know 

 that they are not altogether absent here, as they had not been 

 previously noticed either by Dr. Pitton f or Professor Phillips J, 

 and, although I have paid several visits to BriU, I never before 

 was able to detect them. 



There is also a considerable development of the estuarine sands 

 above the Purbeck beds, forming the summit of the hill. In the inter- 

 calated ironstone bands which are usually associated with these sands, 

 I found a small Paludina, coarsely but strongly ribbed, and appa- 

 rently distinct from any figured and described by Professor Phillips. 

 I have also obtained Paludina subangulata, Phill., and Cyrena 

 "media in the same sands at Wheatly and Horsepath, in Oxfordshire, 

 and also Paludince, many years ago, in the Yale of Wardour, in 

 Wiltshire, there associated with Cyclas or Cyrena, and a portion 

 of the carapace of a Tortoise, perhaps Trionyoc. Whether these 

 sands are really the equivalents of the Hastings Sand, or of the 

 estuarine beds intercalated in the Lower Greensand, as suggested by 

 Professor Philhps, it is certain that they contain definite species of 

 freshwater or estuarine shells over a wide -spread area, and deserve 

 a more careful examination in all the districts where they occur. 

 The Uniones are so rare that I have never yet been fortunate enough 

 to find one ; but Paludince and fragments of Plants are not uncom- 

 mon — and the latter occur at Brill and Wheatly, not only in the iron- 



* Trans. Greol. Soc. 2iid series, vol. iv. 



t " Memoir on the strata below the Chalk." Trans. Geol. Soc. 2nd series, 

 vol. 4. 



I Quarterly Journal of the Geological Society, August, 1858, 



