1890.] NEW YORK ACADEMY OF SCIENCES. 9 



sides were smooth. They contained the worm coral heads that 

 had evidently been the means of making the holes. 



On the beach of the cays north of Nassau great blocks of 

 coral rock are seen that have been dislodged by the waves, and 

 in some places fresh fractures show where large fragments have 

 been broken off. On the south side of the cays the erosion is 

 different. Here the water is quiet and eats slowly under the 

 rock, so that a projecting ledge is formed that marks the height 

 of the tide. 



At some places on Andros, as at Fresh Creek and Nicols Town, 

 the shore is undermined, and great slabs in places have fallen, 

 thus making large cracks. Similar cracks are found inland 

 higher above high-water mark, and have evidently been formed in 

 the same manner as those on the shore. Where the edges of the 

 crack were in contact they had been firmly cemented together, 

 and at intervals along the line of the crack were numerous large 

 holes that had evidently been worn out by the action of rain- 

 water running over the edge. Leading into these holes were 

 channels almost as perfectly formed and rounded as a tin gutter. 



The erosion of the surface will impress every one that visits 

 the Bahamas. Sharp, jagged points project so as to make walk- 

 ing tiresome and annoying. Although there is some sand near 

 the beach west of the Barracks at Nassau, there are no great 

 moving masses such as Heilprin describes as being found in 

 Bermuda.' 



In some places, as on Goat Cay, near Fresh Creek, Andros, the 

 surface is eroded in a peculiar and striking manner. Tliere the 

 rock is worn so as to leave vertical cylindrical masses two or 

 three feet high,- some connected below or half-way up with eacli 

 other, others separate. Their sides and tops are pitted and 

 eroded, so they have evidently been affected by atmospheric 

 agencies. On the ocean side of this cay the erosion from the ac- 

 tion of the surf was so exceedingly rapid, that the rock remained a 

 light yellowish color instead of the dull or dark gray it commonly 

 assumes. The form the rock here presented was even more 

 striking than the cylindrical masses described above. It was 

 worn into innumerable peaks and pinnacles like a miniature 

 mountain range, the points and edges of the pyramidal projec- 

 tions being sharp and clean. As we walked back from the edge 

 of the cay, every gradation could be found between the miniature 

 peaks and the cylindrical masses higher up. And I believe that 

 the latter are what remains after the edges of the little peaks 

 and pyramids have been slowly worn away by the action of 

 atmospheric agencies ; for we have only to round off the points 



1 " The Bermuda Islands," p. 31. 



