1840,] 



of the Great Basaltic District of India. 



97 



those of the Berar valley, and they are of course different from the fossils. 

 I also failed to detect amongst them any of the shells contained in a 

 large collection of recent land and freshwater Testacea from Bengal, pre- 

 sented to the Zoological Society by Mr. Benson. It may therefore be 

 inferred, that the fossils do not belong to recent species. 



Gyrogonites have not yet been observed in any deposit more ancient 

 than the freshwater formations of the basin of Paris. Cj'prides occur 

 in the tertiary strata, and in the Weald clay below the chalk, and per- 

 haps in the Birdiehouse limestone of the Edinburgh coal-field. Of the 

 other five genera discovered in these fossil beds, two have hitherto been 

 found only recent or in tertiary deposits, viz. Limnea and Physa ; and 

 the best characterized specimens of some of the others are referable to 

 the same period. It is therefore extremely probable, that the basalt in 

 which these fossils are imbedded, and which has altered the rocks in 

 which ihej occur, belongs to the tertiary epoch ; but to which period, I 

 fear we have not the means of forming any decided opinion. Though 

 none of the species are recent, yet they are too few and in too ruinous a 

 state to admit of any general conclusions ; although, from the very great 

 number of individuals collected in various localities, without adding 

 any fresh species, it is probable that nearly the whole which exist have 

 been procured. But when the vast extent of the country occupied by 

 the basalt is considered, and that a still greater tract was broken up or 

 disturbed at the time of its eruption, it will not appear improbable, that 

 a rule, founded on the disappearance of marine shells in districts ex- 

 posed to no such extensive causes of destruction of animal life, should 

 not apply. 



In the preceding pages, I have described the fossils discovered by Mr. 

 Geddes and myself in various parts of the Sichel mountains, and the 

 Valley of Berar, extending through the great trap district for 140 miles; 

 and I shall now shortly refer to other localities at great distances from 

 each other, where the same fo&sils have been found in similar rocks, 

 buried under the basalt. 



Other Districts of India in which similar Freshwater Shells 



HAVE BEEN FOUxND. 



Dr. Spilsbury discovered, eighteen miles from Jubalpoor, in an undu- 

 lating plain studded with irregular masses of trap, blocks of " indurated 

 clay," containing casts of fossil shells, for the most part siliceous, and 

 resembling those discovered by Dr. Voysey in the Gawilghur range*. At 



• Journal of the Asiatie Society of Bengal, vol. ii,, p. 205, 



