187(3.] of the Great Indian Desert. 95 



estuarine than truly marine, its habitat is always in water nearly if not quite 

 as salt as the sea. The specimens which I obtained are precisely like those 

 now living on the coast of India. Several cases are known of marine ani- 

 mals (chiefly vertebrata or Crustacea, however) found living in freshwater, 

 and apparently descended without change from ancestors which inhabited 

 the same tract when it was part of the sea, but it is rarer to meet 

 with a marine or estuarine mollusk living on unchanged in inland salt 

 lakes without an outlet, at a distance of 150 miles from the sea and of 

 100 miles from the nearest point to which the tide reaches. The conclu- 

 sion to be drawn from the existence of this mollusk is unmistakeable : it 

 must have inhabited the tract now occupied by the sand-hills and their 

 enclosed ' dhandhs' when that tract was in direct communication with the 

 sea, and probably when it formed part of a large lagoon. 



§ 8. Former existence of an Inlet of the Sea in Eastern Sind. The Ran 

 of Kaehli. — Two further conclusions follow as corollaries, the first that the 

 saltness of the soil or subsoil is due to this tract of country having been the 

 bed of the sea, or of an inlet, the second that the sand-hills must have been 

 formed on the margin of the lagoon, and that probably the lagoon was part- 

 ly filled up and isolated by accumulations of blown sand. 



About 100 miles to the south of Umarkot lies the Ran of Kachh, an 

 immense salt plain covered by salt water when the sea, driven up into it by 

 the south-west monsoon, ponds back the more or less brackish water brought 

 down by the Luni and the few streams which run in from the hills of 

 Kachh. Various theories have been proposed to account for the Ran. It 

 is commonly considered an area of upheaval, a raised sea bottom. This is the 

 view taken by Captain Grant and by my friend Mr. Wynne*, although both 

 speak also of its silting up. I had an opportunity of seeing a portion of 

 the Ran in 1863 and I wrote of it (in 1867 1) " I am disposed to consider 

 (the Ran) the bed of an inlet of the sea filled up by the accumulation of 

 detritus brought down by the rivers. It is just at present in the debate- 

 able state, water part of the year, land another part of course the 



whole may be an area of depression, but further proofs of this are necessary 

 than the fact of a small portion having been sunk and another part raised 

 by the earthquake of 1819." 



It must be borne in mind that there is evidence of slight elevation at 

 several places on the coast of Western India ; such has been noticed in. Sind, 

 Kathiawad, and on the borders of the Ran itself, and the area of the Ran 

 has doubtless shared in the general rise. So far I agree with other obser- 

 vers ; but if I understand them correctly, I infer that they rather regard 

 the Ran as an area of special upheaval, and in this I cannot concur, 



* Memoirs G-eol. Surv. India, IX, pp. 21, 28. 

 t Ibid. VI, p. 31. 



