140 G. F. Eaton — Prehistoric Fauna of Block Island. 



tween Montauk Point and Block Island looks right for such an 

 origin, and strongly so. But considering the effects of tidal 

 scour during the ebb through the narrow passages of the 

 Sound, briefly referred to above, it is plain that the channel is 

 of this kind. Block Island and Montauk Point stretch out 

 under water far toward one another, and therefore the deepen- 

 ing from 12 fathoms to 27 and 30 over the narrow interval is a 

 reasonable result for scour. The loops farther south in the 

 bathymetric lines are too broad to be relied on for any conclu- 

 sion . . . but tidal scour accounts well for the present condi- 

 tion of the region." The case briefly stated is this : In 1890, it 

 was Prof. Dana's opinion that decisive evidence was wanting 

 to prove that the original bed of the Connecticut River passed 

 between Montauk Point and Block Island, for the tidal action, 

 he said, was itself able to scour out such channels as were then 

 supposed to lie on the north and south sides of the bar con- 

 necting the Island with Montauk Point. 



Prof. Dana's bathymetric lines were plotted from soundings 

 taken between 1878 and 1883, as has been already stated. It 

 is a significant fact, and one to be carefully noted, that similar 

 bathymetric lines, plotted from more complete and extended 

 series of soundings, taken off Montauk Point in the years 1895 

 and 1896, show that the channel leading seaward from the bar 

 is longer, deeper, and more pronounced now, than it appeared 

 to be when Prof. Dana wrote that it " looked right " for a river- 

 bed origin. The depression which then appeared to be a mile 

 and a half long is now known to be ten miles long. It is not 

 conceivable that this channel should have been enlarged to so 

 great an extent by the ebbing tides during the past fifteen 

 years ; and the only conclusion possible is that this channel is 

 the old Connecticut River bed, which Prof. Dana considered 

 doubtful because soundings had not been thoroughly taken 

 over the critical region. 



The Shell-heaps. 



Three shell-heaps of considerable size were explored by the 

 writer during the year 1897. They will be mentioned in this 

 paper under the names of the Fort Island Shell-heap, the Mott 

 Shell-heap and the Cemetery Shell-heap. Their position 

 is shown on Plate II. In addition to these, two very 

 small deposits of shells, bones, etc., were discovered by 

 systematic sounding in the immediate vicinity of the Ceme- 

 tery Shell-heap, and a tract of land on the west bluff of the 

 Island was found to contain numerous small deposits mainly 

 composed of fish bones. There is no reason for supposing that 

 these are all the shell-heaps formed during the occupancy of 

 Block Island by the Manissees or their predecessors. On the 

 contrary, . it is quite possible that other deposits are still con- 



