196 LIAS OF ENGLAND AND WALES: 
These beds vary a little in detail at different points, while 
measurements vary also, perhaps owing to the beds being more 
compressed in some places than in others, and to the irregular 
passage from one type of sediment to another. 
In passing eastwards from Lyme Regis, we find traces of the 
lower beds of the Middle Lias in Stonebarrow and Westhay Cliffs. 
Tumbled blocks of the Three Tiers may be observed here and 
there above the platform formed by the "Green Ammonite" and 
" Belemnite Beds," but the strata between the higher and lower 
cliffs are much obscured by a wreck of Cretaceous material. 
In Golden Cap the lower beds of the Middle Lias are well 
exposed in the central portions of the cliff. About 80 feet from 
the base, the Three Tiers stand out prominently above the Green 
Ammonite Beds, and form ledges over which several springs fall 
after traversing gullies in the overlying clay. Large tumbled 
blocks of these Tiers and other rocks protect the base of the cliffa 
and form a small headland. (See Fig. 41, p. 52.) 
The various divisions and their fossils have been described in 
much detail by Mr. E. C. H. Day,* with whose measurements 
my own for the most part agree. The term " Three Tiers " was 
applied by him, to three massive layers of fissile micaceous and 
calcareous sandstone, which form a conspicuous feature in the 
lower part of the high cliffs of Golden Cap. The stone is of much 
the same character as the " Starfish Bed " which occurs at a higher 
horizon, but the Three Tiers are more flaggy. The Tiers are each 
from 2 feet to 4 feet 6 inches in thickness, and are separated 
by 10 to 12 feet of micaceous sandy clay, containing concretionary 
masses of calcareous sandstone. The entire thickness of these 
strata varies from 30 to 40 feet. I obtained, through the late 
Robert Hunter, one specimen of Ammonities margaritatus from 
these beds, and Mr. Day has noted the occurrence in them also 
of A.jfimbriatus, A. Loscombei, and bones of Saurians. 
Above the Three Tiers we have a considerable thickness of 
blue micaceous marls, containing ironstone-nodules, iron-pyrites, 
and small irregular limestone nodules. Mr. Day notes the 
occurrence of Ammonities Loscombei in these beds, as well as 
A. margaritatus. At a height of about 95 or 100 feet above the 
Tiers, there is a nodular bed of bluish-grey micaceous and 
calcareous sandy rock, rather shaly in the upper part and about 
3 feet in thickness. It is conspicuous in Golden Cap. Penta- 
crinus, Belemnites, and Lucina occur in the bed. Between this 
nodular bed and the Starfish Bed, there are about 60 feet of 
micaceous marls, with occasional indurated bands and nodules of 
grey earthy limestone. The entire thickness, about 160 feet, is 
represented in Golden Cap ; but at some points this estimate 
appears to be excessive. 
Above these blue marls and clays come the Starfish Bed, and 
the lower portion of the Laminated beds,f which lie beneath the 
* Day, Quart. Journ. Geol. Soc., vol. six. p. 278 ; see also Wright, Lias Ammo- 
nites (Pal. Soc.), pp. 89, 90. 
t These are the " Sands " shown beneath the Upper Grecnsand, in Horizontal 
Section, Sheet 29. 
