merate no mammalia were obtained. In drawing any conclusions, 

 however, the limited space examined, the diameter of which was not 

 more than six inches, must be borne in mind. 



Lieut. Smith remarks the correspondence of the succession of the 

 strata in the Gangetic Delta, at a depth of from 350 to 480 feet, 

 with that obser\'^ed by Captain Cautley at the base of the Himalaya. 



The nature of the fossil remains and the dimensions of the gravel 

 found at 480 feet from the surface of the ground, the greatest depth 

 hitherto attained, were such as to lead Dr. M'Clelland to the con- 

 clusion, that when these were originally deposited bold rocky moun- 

 tains existed in close proximity to the present site of Calcutta ; and 

 taking his data from the results of personal observation on the trans- 

 porting power of rapid currents, he estimates the distance of these 

 mountains at not greater than twenty or thirty miles. Resting on 

 the bed of coarse conglomerate, the entire depth of which is un- 

 known, although it cannot be less than eighty feet, the bore having 

 pierced it to that extent, there are beds of carbonaceous matter and 

 lacustrine clay bearing the clearest evidence of having been quietly 

 deposited on a marshy surface clothed with vegetation. Ere this 

 could have taken place, the powerful currents indicated by the gravel 

 must have been arrested, and as this could only be effected by a great 

 lowering of the inclination of the bed of the river, we may infer the 

 check arose from the entire subsidence of the range of hills above 

 alluded to. The extent to which this took place it is impossible for 

 us to estimate, but the deposits which the river continued to make 

 would repose upon the depressed masses, and were boring operations 

 to be carried on successfully in such localities they would ultimately 

 expose these again to our observation. Supposing then, as without 

 impropriety we may do, that the rocks of which these hills were 

 composed stretchecl away beneath the conglomerate bed formed by 

 the large gravel borne along by the torrent issuing from them, we 

 are led to believe that had the Fort William boring operations been 

 successfully carried through the entire depth of the conglomerate, 

 the auger would then have impinged on the solid rock, and if so, 

 would the experiment have terminated favourably } 



" When we remember," observes Lieut. Smith, " that the con- 

 glomerate was almost entirely composed of debris from primary rocks, 

 admitting of the inference that the chain of hills itself was formed of 

 members of this series, there can be but little hesitation in replying 

 in the negative." 



" On Pipes or Sandgalls in Chalk." By Joshua Trimmer, Esq., 

 F.G.S. 



In a former paper (Proceedings, vol. iii. p. 185) the author de- 

 scribed two detrital deposits in Norfolk, which appear to have been 

 produced by powerful currents of water. The lowest of these is 

 marked on the surface with numerous furrows and penetrated by 

 cylindrical and funnel-shaped cavities like those of the challi, though 

 in general of smaller dimensions. If these have been caused by the 

 mechanical action of water, they indicate a pause between the two 



