AGASSIZ : BAHAMAS. 135 



with the endless chain of cays extending eastward from Cardenas as fat- 

 as Nuevitas. 



The entrances to the flask-shaped harbors of Bahia Honda, Cabanas, 

 and Mariel are made by breaks tiirough the extension of the barrier 

 reef, which from the Manimar Opening to Cabanas has become ahnost a 

 flinging reef. Beyond Cabanas, and as far east as Matanzas, there are 

 but few patches of corals, one to the westward of Mariel, another ofl:' Man- 

 gles Point to the westward of Havana, and we find corals again on the 

 Jaruco Bank and off Maya Point on the eastern side of the entrance to 

 Matanzas. Tlie absence of corals is undoubtedly due to the great depth 

 immediately oft' shore along that whole stretch of coast line. 



From Cardenas to Nuevitas extends a shore platform varying in width 

 from five to twenty-five miles. The outer edge of this coast shelf is 

 edged for nearly its whole distance by a narrow coral reef extending from 

 three to seven fathoms in depth, or perhaps more. A belt of cays, many 

 of them of great size, like Cay Coco, Cay Romano, and Cay Sabinal (Plate 

 XIII. Figs. 1, 2), lie between the edging reef and the shore, leaving 

 large bays or channels navigable for small boats between their western 

 shores and the main island. Between Cardenas and Cay Coco the cays 

 are smaller, and are either scattered in clusters over the shore plat- 

 form, forming small archipelagos like those off Santa Clara Bay, Sagua 

 la Grande, and Caybarien, or else form a belt more or less parallel 

 with the 100 fathom line (Plate XIII. Figs. 3, 4). 



These cays are the result of erosion combined with the wearing action 

 of the sea. On their sea face we find patches of soboi'uco elevated to a 

 height of from five to fifteen feet. Thq first terrace, formed mainly of 

 soboruco, has been greatly eroded in the district between Cardenas and 

 Nuevitas, and in many cases only small patches of the soboruco are left. 



To the eastward of Cay Confites the edging reef little by little trends 

 toward the shore as the shore platform becomes narrower, and to the 

 east of Nuevitas the reef becomes a fringing reef, forming disconnected 

 patches separated by sandy banks between Maternillos Point and Herra- 

 dura Point. At some places, as oflfthe entrance of Padre and of Nuevitas, 

 the reefs form small reef harbors off" the shore, similar to that of Alfred 

 Sound on Inagua. They are readily distinguished, even at a consider- 

 able distance from the land, by the exquisite emerald color of the enclosea 

 waters. 



The Jaiagua anchorage is an excellent example of the formation of 

 an anchorage behind a coral reef caused by the breaking through of a 

 channel oDPosite the mouth of a river. (Hydrographic Chart, No. 518*.) 



