TIPPER EOCENE (BARTON AND [TPPER BAGSHOT FORMATIONS). 589 



the clayey matrix "between them remains the same, the important 

 species Voluta siisiiensa and a Fusiis ar© confined to this particular 

 horizon, and several fruit-spikes of a peculiar kind have quite recently 

 heen met with in it by Daniel Flynn, of the Coastguard, a very 

 keen and good collector of Barton fossils. Above the Septaria the 

 clay becomes glauconitic and sandy, with few and generally much 

 crushed and eroded fossils, but about 30 feet up we come suddenly 

 on two particularly rich zones, 18 inches apart, from which the coast- 

 guardsmen collect in heavy weather. Chief among the fossils are 

 Rostellaria ampla, Voluta luctatriv, Fiisus pyrus, F. longcevus, Murex 

 mincuv, Cassidaria nodosa, and Ostrea gigantea. A few feet below 

 these zones is a conspicuous band of larger, flattened, light-coloured 

 Septaria, which dips beneath the shingle opposite the Coastguard 

 Station. Succeeding this is dark gritty clay, quickly passing into a 

 fine unctuous pale slate or dark-coloured clay, free from grit and 

 green grains, but weathering slightly rusty and greenish at the 

 partings. Most of the shells in it are small and delicate, and col- 

 lected into pockets, Corhida pisum and Turritella in particular 

 abounding. The bed is 10 to 12 feet thick, and includes another 

 less well-marked zone of flat, light-coloured Septaria, 4 feet from 

 the top. The Middle Barton Clays end in a very distinct shell-bed, 

 made up of comminuted fragments, mainly of Turritella, in a rusty 

 matrix, with occasional fragments of larger shells. In the cliffs it 

 appears as a fulvous band, but it sets, under the influence of salt 

 water, into a very hard stone, and when in this state the flat slabs, 

 a foot or more thick, are hauled up the cliffs and used for the foun- 

 dations of houses. Perfect specimens of Tellina ambigua and T. 

 Branderi are not uncommon on their upper surfaces. The shell- 

 beds are only a foot or two thick at Highclifi", and increase eastward 

 to possibly as much as 15 feet. 



The Middle Barton Clays include all the Septaria-bands that occur 

 in the Barton Series, the lowest of these forming a good landmark 

 for the inferior junction, and the shell-bed an unmistakable line of 

 demarcation for the superior limit. They are about 50 feet thick*, 

 relatively homogeneous, and form the slopes represented in the 

 figure (fig. 2). The middle terrace is formed in the more sandy 

 clay above the lower line of Septaria. 



The fauna of the Middle Division of the Bartons is nearly as rich 

 as that of the lower, and far more characteristic, consisting of 

 upwards of 250 species. Yery few of those peculiar to this stage are, 

 however, either common or conspicuous, and perhaps the only one 

 worth citing is Fusus lima. Some of the grandest species, as Hos- 

 tellaria ampla, Fusus longcevus, and Murex minax, range from the 

 Bracklesham right through the Barton, but attain their finest de- 

 velopment here. Others, such as Cassidaria nodosa, Ficula nexilis, 

 Triton argutum, and Fusus regular-is, pass upward from the Brackles- 

 ham, but do not range beyond the limits of this division. The finest 



* This division is the " Barton Clay " of Dr. Wright, who regards it as 

 50' thick, our measurements being respectively 50' and 53', but it appears as 

 150' thick in Prestvrich. It is described as a "mass of compacli bluish-grey 

 clay with Septaria." 



