65 



JOURNAL OF CONCHOLOGY. 



Vol. 12. JULY, 1907. No. 3. 



ON THE MOLLUSCA OF A RAISED CORAL REEF 

 ON THE RED SEA COAST. 



I'.v W. T. HALL AXi^ R. STAN DEN. 



(Read l)efore the Society, J.inuary gth, t9<->7). 



During the year 1906, Mr. Arthur (t. Marshall, C.E., of Wallington, 

 Surrey, sent for identification to the Manchester Museum a collection 

 of shells obtained by him at Port Sudan, the terminus of a newly 

 constructed railway on the west coast of the Red Sea, near Suakim. 

 These shells we have identified, and although they all belong to 

 modern species at present inhabiting the Red Sea, Mediterranean, and 

 Indo-Pacific region, they nevertheless possess considerable interest. 

 Most of them belong to the larger forms, but on carefully crushing 

 and disintegrating the matrix of comminuted shell and coral enclosed 

 between the valves of some large Cardium suhriigosum we obtained 

 quite a number of minute species, some being of genera which appear 

 to be absent from such lists as we have had an opportunity of con- 

 sulting. This has principally induced us to write a short account of 

 Mr. Marshall's find, in the hope that the record may be of useful 

 interest to students of the subject. 



According to Mr. Marshall's statements the local geological formation 

 is a plateau composed of coral and coralline limestone, extending to 

 a hilly country some fifteen miles inland. The shells — the majority 

 of which, though bleached, are not at all wave-worn, and in some 

 cases still retain traces of their original colour — were obtained from 

 one to two miles from the present coast-line. They were either 

 found lying loose on the weather worn surface of the coral reef, or 

 excavated from the consolidated coralline limestone, masses of which 



