Volk 58. ] THE DEEP BORING AT LYME REGIS. 281 
4, Zone of Ammonites semicostatus, about 19 feet thick. 
3. Zone of Ammonites Bucklandi, be Ortd eA 
2. Zone of Ammonites angulatus, Sa: eae 
1. Zone of Ammonites planorbis, from 22 to 24 _,, 
The Amm,-angulatus beds consist of limestone and shale, in about 
equal proportions ; and the Amm.-planorbis beds, of frequent lime- 
stones, with only thin partings of shale: the limestones being of a 
very pale grey, and some of them drying to nearly white, The 
base of the Amm.-planorbis zone is marked by some thin, brown, 
Jaminated shales, which are crowded with spines of echinoderms, 
The Rheetic Beds. 
At Pinhay Bay a still lower series of limestones comes into view ; 
and these are known as the White Lias, but are now separated from 
the true Lias and are grouped with the Rhetic. These beds are 
about 24 feet thick, and consist of soft, white, marly or earthy lime- 
stones, with thin bands of hard compact limestone ; and some of the 
marly beds contain nodules of compact pale-grey limestone, which 
when weathered-out impart to the rock a conglomeratic appearance. 
The lowest of these beds consist of thin layers of compact bluish 
and of creamy-white limestone; but Mr. Woodward did not observe 
anything exactly like the ‘Cotham Stone’ or ‘ landscape-marble ’ 
which was seen by Dr. Wright at Uplyme. Some fossils have 
been obtained from the upper part of the White Lias; they include 
Protocardium rheticum, Modiola minima, Ostrea liassica, Pecten 
pollua, Pullastra arenicola, Schizodus sp., and Estheria minuta. 
On the west side of Pinhay Bay, the White Lias is thrown down 
out of sight by a fault which has a throw of about 40 feet; but 
the lower part of it is seen again in Charton Bay, where Mr. Wood- 
ward found near the base a thin bed of the variegated Cotham 
Stone, and again at Culverhole Point, where 15 feet of it can be 
seen, with impersistent layers of Cotham Stone at its base. 
Below the White Lias are the Black Shales, sometimes called the 
zone of Avicula contorta. These beds are exposed in Charton Bay, 
but are more or less obscured by slips: they may be 30 feet thick, 
and consist mainly of black papery shales and black shaly clay, with 
one or more thin layers of grey limestone. 
The Rheetic Beds are exposed again near Culverhole Point, and 
more or less of all three divisions are here visible. Mr. H. B. Wood- 
ward gave an account of this section in 1899 (Proc. Geol. Assoc. 
vol. xvi, p. 135), and stated the thicknesses as follows :— 
leet. inches. 
W hite Lias, with impersistent masses of Cotham Stone 
SST ar A ne oh OM la aR about 15 8 
Black Shales, with a bone-bed at the base ...... Ry 18 0 
G ei en Marls, with bands of marly limestone and black 
CE iE ARRON ee oe AN te LN a AAW Ee RR O 
He mentions, however, the existence of ‘slight faults, some of 
which appear to be due to landslipping’; and I am inclined to 
think that the White Lias has here slipped over the upper part of 
