170 



CONCHOLOGICAL NOTES FROM RUSSIA. 



By LIONEL E. ADAMS, B.A. 



(Read before the Society, November 13th, 1907). 



The Tonka of Ararat is a long tongue of sand which forms the 

 entire western seaboard of the Azov, dividing that sea from an inland 

 salt lake called in Russian the Sivash. At its southern extremity the 

 Tonka joins the mainland of the Crimea near the ancient Genoese 

 fort of Arabat, and at the northern end there is a narrow strait con- 

 necting the Azov with the Sivash, across which is a bridge at the town 

 of Ghenitshesk. The length of the Tonka is sixty miles and the 

 breadth varies from a quarter to three-quarters of a mile, except in two 

 places towards the northern end where it widens irregularly to three 

 and a half miles. The Sivash or "Putrid Sea" is a lake of the 

 strongest brine in which animal and vegetable life are alike impossible, 

 for which reason it is locally known as the "Dead Lake." The name 

 "Putrid Sea," given on account of the foetid salt mud on parts of its 

 banks, is thoroughly well deserved. At intervals along the Sivash 

 shore of the Tonka are salt pans whence the salt is obtained by means 

 of evaporation. It was while we were engaged for a month in shipping 

 this salt from various places along the Tonka that I was enabled to 

 gather the material for the present note. A glance at a chart of the 

 Azov will suggest the formation of the Tonka, which, like the three 

 long sand spits on the north coast, was built up by the sweep of the 

 current of the Don issuing from the Gulf of Taganrog, aided by the 

 strong east winds which prevail in autumn. Our Chesil Beach 

 presents a somewhat similar case. The geological formation of the 

 Tonka is interesting conchologically as it is entirely composed of a 

 small cockle {Cardium edule Linn.) which is found in every stage of 

 detrition, and, though never found alive in this part of the Azov, is 

 used as food at Mariupol and Burdiansk. On the surface of the 

 Tonka the shells are ground into fine sand, but below this they form 

 a conglomerate rock, which is quickly disintegrated on exposure to 

 air and damp. Along the coast of the Crimea adjoining the Tonka 

 the same formation occurs, but here the conglomerate, which is much 

 firmer, being presumably considerably more ancient, is mined and 

 quarried for building purposes. In Kertch and Theodosia it is much 

 used for public buildings and seems to resist the extremes of climate 

 as well as most freestones do in England. The height of the Tonka 

 averages about six feet above sea level, though here and there an 

 elevation of ten feet may be reached. There is, of course, no tide in 

 the Azov, but when the strong east winds blow, the water frequently 



