THE BAHAMA ISLANDS 13 



Island and Caicos Banks, which are fringed with low islands, so as to form a 

 crescent with a shallow open lagoon in the interior; fourth, Salt Cay Bank, 

 which is intermediate between first and third classes; fifth, composite banks 

 like the Little and Great Bahama Banks which carry characteristics causing 

 them to resemble all of the others. 



On the larger islands, lakes, ponds and marshes are frequently met with. 

 Many of these are shallow, while others are quite deep and are connected more 

 or less directly with the ocean. They are usually undrained, contain brackish 

 water, and their shores are lined with mangroves and other characteristic salt- 

 loving plants. Examples of these are Lake Killarney and Harold Pond 

 (Plate V, Fig. 1) on New Providence. The shores of these lakes advance 

 and recede with the filling or desiccating of the body of water within. 



One of the most beautiful brackish lakes in the Bahamas is located in the 

 interior of Watlings Island (Plate V, Fig. 2, and Plate XXXII). It is 

 known as Great Lake, contains brackish water, and is reported to be con- 

 nected with the sea beyond. On the day that the Expedition visited this lake, 

 foam from the water had been blown up on the beach into drifts which quivered 

 in the breeze like piles of eider-down. An additional interest is attached to 

 this lake as it is believed to be the one seen by Columbus on the morning of 

 the day when he first touched foot in America. 



In addition to these lakes there are deep, well-like depressions filled with 

 salt water and connected with the ocean by subterranean passages. They ebb 

 and flow with the tide, support marine life, and in all essential features 

 resemble the submarine ocean-holes, except that they occur on land, usually 

 removed some distance from the sea. One of the most perfect of these occurs 

 at Tarpum Bay, just behind the settlement and at a distance of about a 

 quarter of a mile from the sea-shore (Plate IX, Fig. 1). This terrestrial 

 ocean-hole is circular in form and is said to be 100 feet deep. It contains salt 

 water, and one standing on the rim can distinctly see marine fishes swimming 

 about in the water below. The surface of this water changes with the tide and 

 there is no doubt that a subterranean channel connects this hole with the 

 ocean outside. 



There are all gradations between these terrestrial ocean-holes and a 

 smaller type of well-like openings known as " banana-holes." These banana- 

 holes are cylindrical depressions with perpendicular sides and attain at 

 times a depth of 25 feet or more. Their bottoms are usually lined with 

 soil or mud, but at other times contain brackish or salt water which ebbs and 



