942 PROFESSOR J. PRESTWICH ON THE EVIDENCES OF A SHBMERGENCE 
and at the south end of 1370 feet above the sea-level. From the O’Hara Tower, at 
the south end, the Ptock falls rapidly to the Windmill Plain (400 feet), and again to 
the Europa plain (150 feet). These are plains of marine denudation. The strata 
dip at a high angle to the west. On the east side the Pock forms an almost sheer 
precipice: on the west side it slopes rapidly to the sea level, as shown in the follow¬ 
ing sections by Messrs. Pamsay and Geikie, which have the advantage of being 
drawn to a true scale. The interpretation of the drift beds is, however, my own. 
At the foot of the west slope is the belt of lower ground on which the town is situated. 
Fig. 14. — Transverse Sections of the Bock of Gibraltar (after Ramsay and Ge[kie). 
A. Section across Sugar Loaf Hill, O'Hara 
Tower, 1370 feet. 
B. Section across Middle Hill, St. MichaeVs Gate, 
11.38 feet. 
s, sands; a', limestone breccia or rubble-drift (tlie agglomerates of the authors—their older agglomerate 
is that on the left and their newer one that on the right side of the sections) ; L, limestone; S, shale; 
X, ossiferous fissures (not in original sections*) ; c. Raised Beach. 
The Pock has been extensively faulted and fissured. Large rents, some perpen¬ 
dicular, and others inclined at various angles, and extending to great depths, traverse 
it in different directions. They are met with at all heights up to 1100 feet (St. 
Michaels).! In the course of constructing fortification works, ossiferous fissures haY^e 
been discovered from time to time. Amongst the most important is the one known 
as the Genista Cave on Windmill Hill explored by Captain Brome (1862 and 
1868), and investigated paleontologically by Dr. Falconer and Mr. G. Busk in 1865. 
This hill forms a plateau 400 feet above the sea at the south end of the rock. 
Many of the fissures have been only partly filled up by the breccia, leaYung large 
open spaces at various depths, some of Avhich have been occupied as caY^es and places 
of refuge up to comparatively recent times. OYving to the untimely death of 
Dr. Falconer it fell to Mr. Busk to complete the investigation of the fossil fauna, 
commenced by the former.^ 
The folloYving is Mr. Busk’s revised list of the Mammalian remains :—§ 
* Tliese I have merely put in approximately to indicate tlieir general position, bnt not tlieir depth, 
t. Sea-caves and beaches also exist at various heights. (See Mr. Jajies Smith’s paper.) 
X ‘ Palisontological Memoirs,’ vol. 2, p. 554. 
§ ‘ Trans. Zool. Soc.,’ vol 10, p. 53, 1876. 
