96 Dr. Wright on the Geology of the 



This limestone band is not uniform in structure throughout 

 its course. It is of a pale yellow cream colour in some places, 

 dense and compact or light and porous in others. It varies in 

 thickness from 3 to 6 feet, audits compact varieties are used for 

 building purposes. 



How Ledge is formed by this bed stretching under the Solent ; 

 and the rocks at Warden and Alum Point are foundered blocks 

 of Lymnsean limestone. It is very fossiliferous throughout its 

 entire course. The shells are beautifully preserved : as they 

 drop out of the rock they leave cellular cavities ; the interior of 

 the shell being filled for the most part with a more spongy 

 material than that which connects the individual fossils with one 

 another. 



It is impossible to describe the beauty of some of the rocks 

 lying at Warden Point, which appear to be little else than a mass 

 of freshwater shells cemented together by a calcareous matrix. 



The elegant forms of the snow-white shells make a chaste 

 contrast with the yellow rock in which they are imbedded. With 

 a chisel and a light hammer the following specimens may be ob- 

 tained in great perfection : — 



Lymnaea longiscata. Planorbis euomphalus. 



fusiformis. lens. 



columellaris. rotundatus. 



pyramidalis. obtusus. 



minima. Bulimus ellipticns. 



maxima. 



I regard this bed as the uppermost of the lower freshwater 

 formation. 



No. 19. Fawn-coloured sandy clay, with bands of Paludina 

 unicolor in the upper layers ; the lower layers are not so fos- 

 siliferous : measures 6 feet. 



No. 20. Bluish gray sands, no fossils : measures 3 ft. 6 inches. 



No. 21. Blue clay with several scams of shells. Paludina and 

 Melania are very abundant, and fine specimens of Unio Solandri 

 are obtained in good preservation, together with bones of Palceo- 

 thcrium and Trionyx, and a profusion of small black seeds, Car- 

 poliihes ovulum, Brong., C. thalictroides, Brong. It rises south 

 of Colwell Chine. A good section of the bed may be seen at 

 Warden Point : measures 2 feet 6 inches. 



No. 22. Striped clays, gray and bluish, with rich scams of 

 shells, in which Paludina and Melania are most abundant : mea- 

 sures from 6 to 8 feet. 



No. 23. Grayish white sand rises on the shore near Warden 

 Point, passes through the upper part of Weston Chine, and is seen 

 capping the hill south of that gorge; it reappears again beneath 

 the Lymnsean limestone on the north side of Ileadon; here it 



