Contributions to the Fauna of the Bahamas 13 



subsidence must have been only about 40 feet deeper tlian previously believed. 

 From a zoogeographical point of view, however, the contrary is the case. The Bahamas 

 are very low islands. A subsidence of 60 feet would submerge the greater part of 

 them, only leaving the top of the hills as very small and narrow islands, rocky 

 remnants or sand bores. Such a subsidence would put almost the whole island of 

 Å ndros below the surface of the water. The facts given show plainly that the sub- 

 sidence that followed after the period of the elevated state, during which the ocean- 

 holes were excavated, must have been so extensive that the islands were submerged 

 to a level 60 feet below the present one, and that after tliis subsidence there came 

 an elevation raising the islands to the present level. During that time of great sub- 

 sidence not only were the sea-cliff at Mastic Point and the coral reef on Green Cay 



Fig. D. Morgans Bluff, Andros. 



formed, but also many of the corals and marine shells, found in the rocks were depo- 

 sited. That the hurricanes have thrown up many of the named pieces of corals and 

 shells, which then later on have recemented in the rocks, may be the fact in many cases 

 but not in all. During the following elevation new hills of coral and shell sand were 

 piled up and these soon hardened to rocks. To some, but certainly very little extent, 

 the corals have also taken part in building up the present islands. That this very 

 extensive subsidence must have been of the greatest influence on a land fauna, that 

 had previously invaded over possible landconnections or had reached the islands in a 

 passive way is quite evident. It would hardly have been able to survive this sub- 

 mersion. There is also in the present fauna no relicts known from that time. 

 Whether the Bahamas are at present still rising or stationary or subsiding cannot be 

 decided until some time has elapsed. Then this will be shown by the marks, put 

 up for this purpose by the Exped. Geogr. Soc. of Baltimore. 



