128 Dr. T. Wright on the Freshwater and Marine 



versed by seams of carbonaceous clay, and has numerous zones 

 of lacustrine shells and remains of plants. It admits of a sub- 

 division into minor beds ; but in consequence of the debris which 

 covered it, no satisfactory analysis of these could be made. It 

 measures about 20 feet. 



Alex. Pytts Falconer, Esq., obtained from this bed the fine 

 specimens of mammalian remains described by Prof. Owen, con- 

 sisting of the skull, jaws, and many different bones of the skele- 

 ton of Paloplotherium, a new genus of the Palaotherida, with 



Palacotherium (two species). Melanopsis brevis. 



Diehodon, Owen. Lymnsea longiscata. 



Crocodilus Hastingsiae. pyramidalis. 



Trionvx (two species). Melania, n. sp. 



Emys. Potamomya plana. 



Lepidosteus, considerable parts of Small, black, capsular seeds with a 



the skeleton. corrugated integument. 



Paludina lenta. Carpolithes ovulum, Brong. 



Planorbis. C. thalictroides, Brong. 



Ancylus elegans. Seeds of Chara medicaginula. 



No. 15. The " Lignite-bed " rises about half a mile east of 

 Beacon Bunny, and runs out of the cliff about a quarter of a 

 mile west of that gorge, inclining at an angle of 2°. It forms a 

 good line of demarcation in the section. The course of this bed 

 can be traced with a telescope from Colwell, on the opposite shore 

 of the Solent, a distance in a straight line of six miles. It con- 

 sists of a dark-coloured carbonaceous and very tenacious clay, 

 full of shells, with an intercalated band of lignite about 18 inches 

 in thickness, which has been extracted in some places and burned 

 as coal. The shells lie chiefly at the bottom of the bed. Pota- 

 momya angulata, Potamides margaritaceus, Melanopsis brevis, Ne- 

 ritina concava, Cyrena obovata, C. Cycladiformis, Mytilus Brardii, 

 a small-ribbed Modiola, and Serpula tenuis were collected there- 

 from. 



The shells are much crushed, and are preserved with difficulty. 

 Most of my specimens are broken ; the contents of the bed were 

 noted on the spot as the fossils were obtained from the rock. The 

 entire bed, which seems to have been formed in brackish water, 

 measures 3 feet 6 inches. 



The Estuary Formation. 



No. 16. Grayish white sand rises about 300 yards west of 

 Mead End, and runs out at Beacon Bunny, inclined at an angle 

 of 2°. The siliceous particles of this bed are scarcely coherent, 

 and its numerous fossils are consequently not well preserved. It 

 contains an immense quantity of small shells, which are extremely 

 brittle, and very difficult to preserve ; specimens of the following 

 genera air now before me : — 



