54 bulletin: museum of comparative zoology. 



extension, perhaps close to- the edge of the Santaren Channel, is well 

 marked by the great belt of white marl, which we may see formed under 

 our eyes on the shores of Wide Opening. The northern limit is marked 

 by the spread westward and northward of the white marl, with here and 

 there a remnant of the main island as an isolated cay, like Billy or 

 Williams Island, reaching perhaps to the northern extremity of the 

 bank, where the only traces of its former existence are the rocks, islets, 

 and shallow bars extending from Great Isaac to Great Stirrup Cay, 

 forming to the eastward of the northern extension of Andros a broad 

 promontory, of which the Berry Islands and the Joulter Cays are the 

 only remnants. On the west, along the line of the Old Bahama Chan- 

 nel, the Santaren Channel, and the Straits of Florida, we are reminded, 

 by Lobos Cay, Guinchos Cay, and the disconnected flats and patches edg- 

 ing the channel as far as Orange Cay, of the western extension of Andros ; 

 while the Riding Rocks, Gun Cay, and the Bernini Islands, lying be- 

 tween Orange Cay and the Great Isaac, attest the former existence of 

 the shore line of a large island — probably the west coast of Andros — 

 along the eastern edge of the Gulf Stream. 



The appearance of the east coast of Andros, the high seolian bluff of 

 which flanks nearly the whole of the western edge of the Tongue of the 

 Ocean, is in striking contrast to its low western shore. The east face of 

 Andros is a series of alternating beaches and bluffs, extending from the 

 northern extremity to High Point. The island is comparatively well 

 wooded, large tracts being covered by pine and by hard-wood forests. 

 To the south of Morgan's Bluff near the shore begins a magnificent 

 coral reef, extending the whole length of the island, and running paral- 

 lel with and distant from it half a mile to a mile and a quarter, with 

 openings in the outer reef to allow the passage of spongers. This reef, 

 though narrow, is one of the finest reefs I have seen, and the patches 

 of corals and Gorgonians which flourish between the outer reef and the 

 shore are not surpassed in beauty by the corals of any district known 

 to me. These patches form an intricate network, rendering naviga- 

 tion inside the reef very difficult. In fact, it can be followed only by 

 the eye. The inside patches of Gorgonians are in many places most lux- 

 uriant, while the outer reef is mainly made up of masses of Astraeans 

 and Madrepores ; the patches between the outer reef and the shore 

 consist of Porites, Mseandrinse, and Millepores, growing upon the seolian 

 rocks. These coi'als, when broken up by the action of the sea, supplied 

 the sand forming the beaches which cover the underlying seolian rocks. 

 I saw T but few stretches of the shore coral rock formation. 



