44^ EOCENE. 



and the sands in the lower: green grains abound in many of the beds. 

 They appear to have been formed in a quiet estuary, by the sediment 

 brought down by a great river, the changes to the coarser detritus 

 being caused by the state of flood. The climate of this period 

 must have been almost tropical. 



The fossils include Plant-remains, Nipadites, etc. ; the INIollusca, 

 Cardita ( Venericardia) planicosta, Corbula gallica, C. pisitm, Cypraa 

 Boiverhankii, Solen obliquus, Psammohia CEstuarina {^Sanguinolaria 

 Holloivaysii), Ostrea flahelliila, Pec ten corneus, Cytherea suherycmoides, 

 Cerithiiini giganteum (which attains a length of 2 feet in the Paris 

 Basin), C. coniucopicE, Pleiirotoma aticfttia/a, Voliita Selseietisis, V. 

 cithara. Conns deperditiis, Tiirritella multisulcata, T. sulcifera, 

 T. imbricafaria, etc.; the Coral, LttharcEa Websteri; the Foramini- 

 fera, Nunwiulvia IcBvigata, N. variolan'a, and Alveolina fusiformis ; 

 the Fishes, Myliobatis toliapicus, ^iobatis, Otodus obliquus, Lamna 

 elegans, and C archarodon heterodon ; Reptiles, PalcEopMs typhczus, 

 Chelone; and Mammals, Lophiodon, etc. 



Fossils have been obtained south-east of Bracklesham, at the Houngate 

 Rocks in Bracklesham Bay, and north-east of Selsea ; at Stubbington, north-west 

 of Gosport ; at Whitecliff and Alum Bays in the Isle of Wight. Uur knowledge 

 of the fossils is largely due to collections made by Mr. F. E. Edwards, Mr. F. 

 Dixon, Dr. Bowerbank and others. It has been remarked that although 

 Bracklesham Bay affords at some tides and seasons the most abundant harvest to 

 the palaeontologist, yet it may happen, owing either to the wind covering the beds 

 with sand, sometimes to two or three feet in thickness, or to the tide not leaving 

 the shore sufficiently exposed, that no fossils can be procured. The best time for 

 collecting is the first two days before, and the last three days after, the full and new 

 moon ; the lowest tides are generally in March and October. When the beds are 

 visited under favourable circumstances, there is an exposure, at one view, of an 

 immense horizontal surface of fossils, among which Cardita ptaaicosta and 

 Ttirritella hnbrkataria are prominent forms.' 



South of Selsea Bill, the Clibs and Mixen rocks consist of arenaceous lime- 

 stone, made up oi Alvcotiiia and other Foraminifera (Alveolina limestone). These 

 rocks and also the Houngate Rocks have yielded building-stone for houses at 

 Selsea. 



In Alum Bay the Bracklesham Beds consist of clays and marls, 

 overlaid by white, yellow, and crimson sands. The lower beds are 

 remarkable for the lignite they contain, which is found in solid 

 beds from fifteen inches to over two feet in thickness. Like true 

 coal, each bed is based upon a stratum of clay, containing ap- 

 parently the rootlets of plants. The deposit is a little more than 

 100 feet in thickness. In Whitecliff Bay the series is thicker, and 

 the lower beds, consisting of green clayey sands, yield Cardita 

 planicosta and Turritclla imbricataria : the former species giving 

 name to the Cardita bed. A bed of conglomerate, formed of 

 flint-pebbles, constitutes a strongly-defined division between the 

 Bracklesham Beds and the Barton Clay.'* 



^ Dixon, Geol. Sussex, ed. 2, p. 58 ; Fisher, Q. J. xviii. 82. Many of the 

 fossils are extremely delicate ; and owing to their perishable condition, in order to 

 preserve them Mr. Fisher recommends their being steeped in isinglass dissolved in 

 gin, while Mr. Dixon used a mixture of diamond-cement and water. 



2 H. W. Bristow, Geol. I. of Wight, p. 43. 



