Results of Microscopical Examination of Soundings. 143 



tertiary deposits. Their entire absence in the deep sound- 

 ings, where vast numbers of other Polythalamia occur, and 

 their presence in littoral deposits, would seem to indicate 

 that for their abundant development comparatively shallow 

 seas are necessary ; thus affording additional evidence of 

 difference in the depths of the seas from which the cretaceous 

 and tertiary bed were deposited. 



5th, The deep soundings were all from localities which are 

 more or less under the influence of the Gulf Stream, and it 

 is not improbable that the high temperature of the waters 

 along the oceanic current may be the cause of immense deve- 

 lopment of organic life, making its path, as is shewn by the 

 soundings, a perfect milky way of Polythalamia forms. The 

 deposits under Charleston may have been produced under 

 the similar influence of an ancient Gulf Stream. 



6th, From the presence of such great numbers of Polytha- 

 lamia in the deep soundings, there results a very large pro- 

 portion of calcareous matter, thus presenting a striking dif- 

 ference between them and the quartzose and felspathie sands 

 nearer shore. 



1th, The littoral sands obtained in shallow soundings at 

 first view appear to give little promise of affording any In- 

 fusoria. But notwithstanding their coarse, and, in some 

 cases, even gravelly nature, they all yield by levigation a 

 considerable number of siliceous Infusoria, which, in variety 

 and abundance, exceed those found in the deep soundings. 



8th, None of the soundings present anything resembling 

 the vast accumulations of Infusoria which occur in the 

 Miocene infusorial marls of Virginia and Maryland ; and 

 indeed, I have never found, even in estuaries, any recent 

 deposit at all resembling the fossil ones, in abundance and 

 variety of species, with the exception of the mud of a small 

 creek opening into the Atlantic near Rockaway, Long Island. 



9th, The occurrence of the pebble of limestone with encri- 

 nal plates in the gravel of F. No. 10, south-east of Little 

 Egg Harbour, is of some interest, as the nearest beds from 

 which it could have come are the Silurian formations of 

 Pennsylvania or northern New Jersey. It indicates a trans- 

 portation of drift to a considerable distance seaward. 



