AGASSIZ: BAHAMAS. 85 



THE EASTERN BAHAMA ISLANDS. 



Plate I. ; Plate VI. Figs. 1 to .4 ; .Plate IX. 



To the eastward and southeastward, and separated from the Great 

 Bahama Bank by very deep channels, are a series of islands and banks 

 extending from Watling Island to Xavidad Bank, which in their turn 

 rise sharply from the bottom of the ocean. These islands and banks 

 are of all shapes, either elliptical, or circular, or more or less rectangular, 

 or sometimes irregularly triangular. They are interesting as showing 

 the different stages through which the Bahamas as a whole have passed, 

 from the time when they covered a far greater area than that now 

 indicated by the islands, which in some cases mei'ely form the sea fringe 

 of the banks of which they represent the summits. The former isl- 

 ands have been eroded and eaten away, and have wholly disappeared 

 on the western faces of the banks, or have left only here and there a 

 small island or isolated rock to testify to the former existence of the 

 same seolian hills which form the summits of the present islands. 



The smaller islands — like Watling, Conception, Rum Cay, At wood 

 Cay, the Plana Cays, Mariguana, and the Inaguas — still occupy nearly 

 the whole area of the banks upon which they rise. The 100 fathom 

 line of Great and Little Inagua, of Samana, and of Mariguana, is but a 

 little distance beyond the shore line of these islands. On Rum Cay and 

 Watling the 100 fathom line bank is somewhat larger, and Conception 

 Island is a small part of the submerged bank upon which it rises. But 

 except Conception these islands have at no time differed very materially 

 from their present outline. When, however, we come to such banks as 

 the Crooked Island Bank, Caicos Bank, and Turk's Islands, we find upon 

 them a series of islands which have been greatly modified by the action 

 of the sea. The islands, such as Crooked Island, Fortune Island, Bird 

 Rock, the Fish Cays, Acklin, and Castle Island, which, with the exception 

 of the westward face, nearly surround the Crooked Island Bank, are all 

 that remain of the one large island which undoubtedly once occupied 

 the whole of this bank even somewhat beyond the 10 fathom line. In 

 fact, we may well imagine the time when the Crooked Island -Bank 

 presented much the same appearance as Great Inagua, when it had like 

 the latter its fringing reef a short distance from the shore line at a depth 

 of four to fifteen fathoms, and formed perhaps here and there a reef 

 harbor like that of Alfred Sound at the northwest extremity of Inagua. 



