68 LIAS OF ENGLAND AND WALES: 
from a precise indication of the zone, he states that he recognized 
several fossils belonging to it, " as, for example, A. Valdani and 
A. Maugenestif in greyish-coloured clay beneath a bed with 
A. Davcei."* 
From these remarks it may be inferred that the main litho- 
logical divisions, which we are able to make in the Lower 
Lias of Dorsetshire, do not correspond at all precisely with 
the ranges of the zonal species of Ammonites : an inference, 
the truth of which is confirmed by a study of the Lias in other 
parts of the country. We have in fact, on the Dorsetshire 
coast, as elsewhere, an inosculation of the zones which prevents 
our marking rigid limits for them. 
The following are the details of the Belemnite Beds : 
FT. IN. 
Belemnite Stone. Hard pale-grey uneven 
marly limestone - 6 to 8 
Dark shaly marls with much iron- pyrites, and 
pyritic fossils ; with nodules and impersistent 
Zones of 
Ammonites 
Ibex, A. 
Jamesoni, and 
A. armatus. 
about 80 feet. 
masses of hard grey limestone, within two feet 
of the Belemnite Stone - - 6 
Pale grey marls - - - - 35 
Hard marly limestone and hard pale and dark 
grey marls, forming ledges in the gullies of 
Stonebarrow Cliff over which springs fall. 
Thickness variable - - - - 6 
Grey shaly and micaceous marls - 30 
I Marly limestones and shales - - 1 
(_Shales 10 
Grey earthy limestone (top of Black Marl series). 
4. Green Ammonite Beds. Above the Belemnite Beds comes a 
series of bluish-grey micaceous marly clays, with occasional 
indurated bands, nodules of hard grey limestone, and ferruginous 
layers, altogether about 105 feet thick. Towards the lower part 
of the series the limestone-nodules are most abundant and 
frequently contain specimens of Ammonites latcecosta, Sow. 
These when cut and polished are sold under the name of " Green 
Ammonites " because the spar filling the chambers is often of a 
green colour. The same Ammonite is abundant in the marly 
beds, but usually in a fragmentary state. Hence the name " Green 
Ammonite Beds," adopted by Mr. Day, and which may be used 
as a general term for the marls between the Belemnite Stone and 
the Three Tiers.f 
Traces of these beds first appear in Black Ven, although on 
account of the slips and the difficulty of getting at the strata, they 
cannot be well examined. Proceeding eastwards they occur 
above the Belemnite Beds in Stonebarrow Cliff, and although 
traces of the Tiers are found in places, showing that the entire 
thickness of the beds is represented, only the lower portion is 
there -well exposed. The beds however are clearly shown 
beneath the Three Tiers in Goldeii Cap. Commencing east of 
St. Gabriel's Water, they are exposed along the base of the cliffs^ 
above the Belemnite Beds (which appear here and there), as far as 
* Lias Ammonites, pp. 83-89. 
f Dy, Quart. Journ. Geol. Sec., vol. xix. p. 278. 
