Fig. 1. 
5 
MARINE BIOLOGY OF THE SUDANESE RED SEA. 
PLATE 2. 
General view of the cliffs eastwards of Alexandria. The rocks in the foreground are 
made of rubble consolidated by the sea, the similarly situated reef in the middle 
distance is natural sandstone. 
2. Hill of rubble at Chatby, Alexandria, remaining after the surrounding land has been 
excavated to its original level. | 
3. Portion of cliff face situated between 2 and 1 above. The upper part of loose rubble 
Bis de 
containing pottery, &c. : the lower of very soft sandstone. 
PLATE 3. 
Catacomb passages exposed by the sea, in the same locality as above. The cliffis 
coherent sand below, rubble &c. above, as in Pl. 2. fig. 3. Eight niches for bodies 
can be made out in the foreground, to the left of the main passage. 
. The “ Spouting Rock” beyond Palais station, showing the regular shelf surrounding 
the rock just below water-level and partially laid bare during the retreat of a 
wave. 
PLATE 4. 
Jebel Tétawib, in Khor Dongonab, a butt near its southern extremity, seen from its south side. 
NG 
B. 
G. 
H 
The letter B is at a level about 25 feet above the foreground. 
Coral colonies, in position of growth, bedded in a mass of loose coral débris, 
shells, &c. 
Corals bedded in consolidated coral-mud, forming a harder layer than that formed by 
either constituent alone and so projecting shelfwise at B. This layer passes 
eradually into C, 
. Hardened coral-mud. The weathered surface forms rounded masses in low 
relief. 
. Gypsum strata, here steeply tilted, and upturned at their ends in the piece shown 
in the foreground, They are much folded in other parts of the cliff. 
. Green and red shaly rock underlying and sometimes interstratified with the 
gypsum. It is here broken down into sand. This rock contains sheets of glass- 
like recrystallized gypsum. 
. A fallen piece of B. Contrast its roughness with the smooth rounded surfaces of C 
upon which it lies. 
Scree material from A & B, consisting of coral and shells. 
A dark line of reddish broken shell-material, containing many Cidaris-spines. This 
is more prominent in some other parts of the hill. 
