402 
THE CRETACEOUS ROCKS OF BRITAIN. 
The following account lias been taken chiefly from the notes of 
Mr. Rhodes feet. 
Chalk with frequent bands of flint nodules, inaccessible, but 
specimens of Micraster cortestudinarium and Echinocorys 
vulgaris found on the pit floor seem to have come from this 40 
Chalk with several layers of yellow and green-coated nodules, 
and a hard yellowish bed at the base ; flints rare and 
scattered (zone of Hoi. planus ) - - - - - -12 
Compact homogeneous white chalk, with several thin layers 
of grey marl; no flints except quite at the top, where there 
is a single layer of small black flints. Fossils found princi¬ 
pally about 20 feet from the top ------ 80 
Hard chalk, with a marked nodular bed at the top (zone of 
Rhynch. Cuvieri ) ------- seen for 8 
140 
Lower beds, including the Melbourn Rock, can be seen in the 
road-cutting which leads to the quarry. The beds dip at an angle 
of 10 to 12° to the north. 
The Ranscombe Quarry, a little farther west, must have shown 
a similar section in 1875, as described by Prof. Barrois, who was 
fortunate in obtaining five species of Ammonites from it, but it 
is now disused and obscured by talus. 
Southerham Limekiln Quarry, the position of which is indi¬ 
cated in Pig. 66, must once have shown a fine section through 
the whole of the Middle Chalk. It has been mentioned bv Mantell 
«/ 
and Martin, and in all probability the former obtained many 
fossils from it. The present workings, however, are chiefly at 
the northern end in the higher zones, and the southern part of 
the great excavation is much obscured and overgrown. The beds 
have a northerly dip of about 25°. 
At the southern end, however, Mr. Rhodes found a small ex¬ 
posure of the Melbourn Rock, succeeded by rough shelly 
chalk with Inoceramus mytiloides and Rhynchonella Cuvieri. 
The top of this zone is marked by a bed of hard chalk about a foot 
thick, yellowish, and containing some yellow-coated nodules. 
Above this are small exposures in the T erebratulina zone. 
The Mailing quarries lie to the north-east of Lewes, at the north 
end of the section Fig. 71, and that called the “ new pit ” must 
formerly have shown an excellent vertical cut through the Tere¬ 
bratulina zone. Mr. Rhodes reports that the quarry is about 
120 feet deep, but that the lower part is now much obscured 
b}^ talus and grass ; the upper face shows the following beds : — 
feet. 
Rough chalk with scattered flints and two layers of flints 
near the top, below a seam of marl (this chalk is not 
accessible) - -- -- -- - about 
Massive white chalk without flints (Holaster 
planus). ------- about 
Terebra- Seam of grey marl. 
tulina White chalk without flints, containing Ter. gracilis 
Zone. var. lata , Galerites subrotundus, and Ammonites 
[. Pachydiscus ] peramplus - seen for about 
40 
10 
20 
