312 
MR. W. BATESOll OX SOME VARIATIONS OE CARDIUM EDULE 
These sliells are nearly all of the very large and thick type spoken of above {vide 
p. 309) as “ great shells.” From the great abundance of shells of this type in the 
deposits below the present bed of Abu Kir, it seems clear that they were numerous in 
the locality for a long period. As they are entirely absent among the shells now 
lying on the shores of the lake (namely, those which were the last inhabitants), I 
would suggest that these “ great shells ” perhaps lived there in the period when the 
sea communicated with the lake. This becomes still more probable in connection with 
the fact of the occurrence of similar shells at Jaksi Klich, Jaman Klich, and on the 
flats between them a.nd Shumish Kul, for at the time when these localities were 
under water and connected with the Aral Sea the conditions in them could not have 
been very different from those prevailing in the lagoon of Abu Kir when it was open 
to the Mediterranean. The shells, then, of Abu Kir are of two kinds :— 
(1.) Shells of animals lately extinct, which lived in a lagoon of water having a 
specific gravity of about I'O.a ; these shells show the same variations from the 
“ normal ” type as those of the Aral district living under similar circumstances. 
(2.) “ Great shells ” occurring in a more or less definite bed below the level of the 
present lagoon, the origin of which is uncertain, but which were probably living when 
the lagoon was open to the sea. 
Mareotis and the Fresh-ivater Lakes at Ramleh. 
The Lake Mareotis is now divided by an embankment into an eastern and western 
part, which differ from each other entirely. 
The western lake is full of red brine-water, and beneath the water is a permanent 
crust of salt. 
I did not succeed in finding any shells on the shore of this portion, though, no 
doubt. Cockles lived in it before the changes were made which have led to its present 
condition. 
The eastern lake contained about 1 to 3 feet of water in most places in April, 1888. 
A very small stream of sea water runs into it near Meks. A t the time of my visit its 
density was about that of the Mediterranean, but it, no doubt, varies greatly with 
the time of year and the state of the Nile. The lake, which lies 8 feet below the 
surface of the Mediterranean, is stated to have been nearly dry at the end of the last 
century, but in the course of military operations in 1801 it was again opened to the 
sea by the English. Possibly, then, the shells now found on its shore are the descen¬ 
dants of those then admitted from the Mediterranean. Another opening was lately 
made from the sea, but has been nearly closed, the small stream of water from the 
sea mentioned above being due to this opening. 
At high Nile tlie level of the lake rises, owing to the infiltration of fresh water, and 
probably it is brackish at tins seasoii. From tliese considerations and fi'om the many 
vicissitudes that the lake has undergone, it is clear that nothing can be stated with 
