BEMBRIDGE LIMESTONE. I(j9 



5. Greenish white limestone, v^ery concretionary and fossiliferous. Small 

 patches of a white mineral are highly distinctive of this hand. Limncea 

 /oiif/iscafa is the most ahundant fossil. Of oLher shells I find in this locality 

 Planorbis discus, P. rotundatus, P. Sowerbii, and P. obtusus, a new Paludina 

 (identical with that in iN'o. 1), Helix occlusa, H. labyrinthica, and two other 

 species. The uppermost 6 inches are very conu^lomeratic. This cap weathers 

 pebbly, and contains freshwater shells ; when removed by the action of the 

 waters the stone below weathers with a rough and pinnacled surface, speckled 

 by the white mineral and very shelly. The substance of the bed is much less 

 shelly below. The thickness at the margin of the bay is 4 ft. 3 in. 



4. Pale, often white marly limestone, in some places becoming very 

 compact ; remarkable for abounding in myriads of a small, rather globose 

 Paludina (P. globuloides) ; containing also Lirnncea lonyiscata, a small 

 Hydrobia, and. more rarely, Cyclostoma mumia. When this bed is much 

 exposed superficially it forms a flat white platform, with an undulated and 

 much cracked surface, the cracks extending throughout its thickness. In its 

 uppermost part is a paleish carbonaceous strip abounding in comminuted 

 shells of Cyrence. The Chara tuberculata occurs in it. 3 ft. 



3. Compact creamy yellow limestone, abounding in casts of Limncea 

 longiscata, of which parts of it seem almost entirely made up ; also Planorbis 

 oligyratus? The nucules of CA«ra tuberculata occur in this bed, but not so 

 plentifully as in No. 1. The uppermost portion of it is conglomeratic. 

 5 ft. 6 in. This is the bed most sought after here for building, yielding 

 blocks of considerable dimensions. 



2. Greenish grey marly clay, with an irregular and crumbling fracture ; it 

 contains crushed shells of Limncea longiscata and Planorbides. 4 ft. 6 in. 



1. Yellowish compact limestone, weathering rather darker, exhibiting in the 

 fracture minute confervoid ramifying cavities. This bed is very full of casts 

 Limncea longiscata and nucules of Chara tuberculata are scattered abundantly 

 through its substance. A small Paludina, a Hydrobia, and a Planorbis 

 (oligyratus) occur occasionally. The average thickness is 3 ft. 6 in. 



Total thickness at WhiteclifF Bay, as exposed in November 

 1853, 24 ft. 3 in. When measured near the same spot by Captain 

 Ibbetson and Professor Forbes in 1854, it was made 27 feet. < 

 Professor Prestvvich, in his section, states the thickness as 

 26 feet. 



The fauna of the Bembridge Limestone has been very carefully 



collected. As a rule it consists entirely of freshwater mollusca. 



In a few places, however, abundance of land shells have also 



been obtained, and in others, as at Headon Hill and Binstead, 



mammalian remains are not uncommon. The lanrl shells comprise 



Fig. 56. tropical -looking gigantic species oi' Bulimus 



Chnra tuhercu- ^^^ Achatina (see pp. 159, 162). Among 



, , J 1, the mammals Anoj^lotlierium, Chcei-opotamus, 



' -' ' Hijopotainns, and FalcEotherium are the most 



abundant. Very little is yet knoMrn about the 



associated plants, for though nucules of Chara 



(Fig. 56), are abundant, the limestone seldom 



yields determinable leaves or fruit of the higher 



orders. Near Foreland Point the palm leal 



{Palmacites) figured by Dr. Mantell in the " Geological Excursions 



round the Isle of Wight," 1854, p. 311, is said to have been found 



in one of the beds of the Bembridge limestone, but the specimen 



is in an ironstone nodule. 



