208 



Mr. W. Bateson. 



[June 6, 



Abu Kir, in Egypt. Shells of this type would appear to be in some 

 •manner associated with life in lagoons opening to a sea, as all the 

 looalities in which they occurred were of this type. None were found 

 at Shumish Kul or in the Aral Sea itself. 



Cardium edule from Lagoons in Egypt. 



I collected shells of G. edule from the district of Mareotis and Abu 

 Kir in order to compare them with those of the Aral Sea. 



Abu Kir has now been pumped dry. In 1888 it was a shallow salt 

 lake, having an area of about 20 square miles. In April, 1888, the 

 specific gravity of the water was T05. No living shells were found 

 in it, but its shores were covered with vast quantities of thin, elon- 

 gated, highly-coloured shells, closely resembling those of Jaman Klich. 

 These shells were plainly those which had last lived in the lagoon, 

 and it may be supposed that they lived in it under conditions not 

 greatly different from those now prevailing. 



Mareotis. — This is a closed lake lying about 8 feet below the 

 surface of the Mediterranean. At the time of my visit, in April, 

 1888, the density of the water was about the same as that of the 

 Mediterranean. It is stated to be brackish at high Mle owing to the 

 infiltration of fresh water, though in summer it probably becomes 

 Salter than the sea. On its shores I found quantities of shells of 

 Cardium edule. There are, apparently, none now living in Mareotis. 

 The absence of living animals may be due to the annual changes 

 which the quality of the water of the lake undergoes, but it is more 

 likely that they have all been exterminated by some of the engineer- 

 ing operations which have at various times been made by different 

 Governments. The shells found on the shore had definite characters. 

 They were elongated shells, moderately thin in texture, having the 

 anterior 6 — 10 ribs yellowish- white in colour, and the portion 

 7 — 12 bluish or chocolate-coloured. The inside of the shells is much 

 ribbed ; the posterior part is generally chocolate-coloured, and some- 

 times this colour extends to the whole interior of the shell. (For 

 particulars of texture and shape, see tables.) The peculiarities in 

 colour and shape of these shells are so great that they could not be 

 mistaken for those of any other locality. 



Bamleh Lake No. 1. — By the formation of the Mahmudiyeh Canal 

 (1819) a small piece of water was cut off from Mareotis near Sidi 

 Gaber Station. This lake is about a mile in diameter. Its water is 

 now fresh, and is kept so by the waste water from the irrigations 

 which flows into it. It is about 10 — 12 feet deep in the middle. 

 Many dead cockle-shells were found in it, but no live ones. These 

 shells have quite definite characters, being very thick and coarse in 

 texture, with 14 — 16 anterior ribs white, and 3 — 6 posterior ribs 



