457 
them are again seen in some of the superior strata : but the characters 
of the greater part are such as to point them out decidedly as peculiar 
to this stratum. 
In this stratum the fossil shells are exceedingly numerous : parti- 
cularly ammonites, nautilitce, terehratulitce, gryphiiee, mytulitce, mo- 
diolitce, spondylites, trigonitee, helemnitee, and the large donaoc -formed 
bivalve mentioned p. 182. In this stratum are also found fish of an 
unknown genus, with large square scales, PI. XVIII. Fig. 9, and 
several species of Testudo, Lacerta, Sec. 
It is to this stratum that the pentacrinitce seem particularly to be- 
long. These fossil remains occur with great frequency on the Dor- 
setshire coast. When the vertebrae of this animal appear in any of 
the superior strata, it is most probable, that they are alluvial, having 
been washed out of the raised or basseting edges of this stratum, by 
that ocean which deposited the stratum in which they are found. The 
confinement of the remains of this genus of animals to so low a 
stratum, is very extraordinary, since we have seen, that animals of this 
genus exist in the present ocean. 
Immediately above this stratum is a blue marl-stone, called the 
Maidwell limestone, with the fossils of which I am unacquainted. 
Nor am I able to speak with more information of a great number and 
thickness of sands and clays which lie over the Maidwell limestone. 
To these succeed the Bath free-stone strata, which may be 
traced in their range through the island. The upper part is a white 
or light grey limestone ; beneath which is the oolithe, or row -stone, 
and under this a considerable thickness of very light-coloured free- 
stone, then sand and clays, and a free-stone of various hues of yellow 
and red. 
The fossils of this strata are chiefly bivalve shells, of which gene- 
rally only the casts, or the impressions remain. The casts are chiefly 
of arks, bucarditee, (of Plott) a shell whose genus is not yet known, 
trigonitee, mytulitce, and various other bivalves, the casts or impres- 
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VOL. III. 
