1897.] NEAV YORK ACADEMY OF SCIENCES. 107 



parish, on the northerly side of Hamilton harbor. It was recog- 

 nized on Tucker's Island, in the Great Sound, on Somerset 

 Island, as well as at several places on St. George. It was 

 reached in a boring at the dockyard excavation on Ireland 

 Island. 



This rock is hard and durable. It was used in constructing 

 many of the Government buildings and the old quarries near St. 

 George, Paynter's vale, on Castle harbor, and at several locali- 

 ties, along the south shore, afford excellent exposures. The 

 texture varies ; sometimes the grain is so fine and close that a 

 good polish can be given ; at others it is comparatively open, 

 though firmly cemented, but there appears to be no relation be- 

 tween texture and stratigraphical position. The color is from 

 bluish white to yellow and almost pure white. The rock is 

 laminated, with wind-drift structure, though this feature is not 

 always distinct in the fine-grained variety, which sometimes, on 

 the south shore, seems to be massive. But this is an excep- 

 tional condition, and ordinarily, the laminated structure is 

 shown at a few yards away. Sometimes the rock is as inco- 

 herent as the softer sandstone and resembles that rock com- 

 pletely, as in some thin beds at the bottom of the Pa3mter vale 

 quarry, on Castle harbor. This condition is exceedingly rare, 

 but is of interest as showing a similar origin for both rocks. 



The direction of lamination along the south shore is as irreg- 

 ular as on Castle harbor — sometimes seaward, as often landward. 

 Ordinarily there is no diflflculty in distinguishing this from the 

 sandstone, there being not only great difference in hardness but 

 a genuine non-conformability of erosion ; occasionally, however, 

 as between Castle harbor and Harrington sound, the sandstone 

 is as firmly cemented in some layers as is the limetone and the 

 rocks cannot be distinguished in hand specimens. 



Fossils of all sorts appear to be absent. The writer's search 

 was unsuccessful everywhere. 



If one may judge from structure and distribution, there is no 

 escape from the conclusion that the visible rocks of the Bermudas 

 are aeolian, the exceptions being local, such as were formed on 

 the shores of channel-ways or within lagoons during subsidence, 

 insignificant fragments of the marine deposit surrounding the 

 area. 



Surface Conditions in the Bermudas. 



Rainfall is abundant in the Bermudas, especially during the 

 winter, but owing to the porosity of the rocks a great part finds 

 its way to the sea through underground passages. Surface flow 

 is insignificant except during storms, when it is apt to be tor- 



