MIDDLE CHALK—SUSSEX. 
397 
In 1895 Mr. Rhodes, the fossil collector of the Survey, was sent 
to collect from the fine series of sections near Lewes, zone by zone, 
so that we might possess more complete data with respect to the 
distribution of fossils at that locality. 
Lastly, in 1896 and 1897 Mr. W. Hill carefully examined and 
measured the coast section near Beachy Head, and also visited 
some of the inland sections, for the purpose of forming an opinion 
on certain questions that had arisen. 
The following account is drawn up principally from Mr. Hill’s 
observations and measurements, supplemented by the information 
obtained by the observers above mentioned. 
As Sussex possesses a good cliff section we have thought it desir¬ 
able to commence with a description of this, and afterwards to 
give some account of the more important inland sections, as they 
are met with in going westward. 
1. The Coast Section. 
The cliffs between Eastbourne and Beachy Head exhibit a com¬ 
plete section through the Middle Chalk, and every part of it can 
be examined either in or below the large quarries at Holywell, or 
in the cliffs west of Beachy Head Coastguard Station, where the 
dip carries each bed successively below the level of the beach. 
The following account is from notes taken by Mr. Hill : — 
At Holywell Bay the Melbourn Rock is but a few feet above 
the level of the shingle, while the highest part of the quarry ex¬ 
poses the lumpy chalk lying just below the Holaster planus zone. 
At Holywell the Melbourn Rock is about 23 feet thick ; its lower 
part consists chiefly of hard whitish nodular and rocky chalk in 
regular courses from one to two feet thick, separated by seams of 
marl, but there are two courses of nearly smooth homogeneous 
chalk ; the upper part is in more massive beds of hard yellowish 
chalk, with layers of very hard, cream-coloured nodules. This 
rocky chalk passes up into less hard chalk with only a few layers 
of nodules, but still rather rough, and yellowish or creamy in 
tint, and containing numerous fragments of Inoceramus-shell. 
Inoceramus mytiloides is abundant in these beds, but Rhynchonella 
Cuvieri is much less common ; their thickness is about 60 feet, 
which, with the 23 feet of Melbourn Rock, gives 83 feet for the 
zone of Rhynch. Cuvieri. 
This shelly chalk gives place somewhat abruptly to the softer, 
whiter, and more massively-bedded chalk of the Terebratulina 
zone, which has here a thickness of about 133 feet, but 
in the upper 12 or 15 feet it becomes lumpy and uneven in texture, 
containing also a few scattered flints. 
Dr. Rowe has more recently measured this zone, and estimates 
its thickness at 170 feet.* Mr. Hill’s measurements are given 
* Proc. Geol. Assoc., Vol. xvi. p. 322 (1900). 
