252 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



from the south shore reef towards the main island are the remnants of 

 the platforms of rocks once rising above high- water mark, or forming 

 perhaps small islands, rocks, and islets across the bays of the proto-Ber- 

 mudian land. We find to-day such islands and rocks separating Castle 

 Harbor from the sea, those across the mouth of St. George, or islands 

 belonging to an outer line of ledges which may be entirely disconnected 

 from land promontories, or form, as they do across Whale Bay, Sinky 

 Bay, and parts of other bays, an outer barrier protecting the south shore 

 somewhat from the beating of the surf till they have crumbled and in 

 turn been reduced to ledges bare only at low-water mark. The true 

 character of many of the ledges forming the flats or the connecting 

 patches is hidden by the coral growth. But both on the north and on 

 the south shore we can follow the passage of the aeolian rock ledges 

 as they recede from the shore, from nearly bare ledges still connected 

 with the shore cliffs to the coral patches. The ledge at Briggs Flat is 

 mainly covered with Gorgonians and Millepores. We find there but few 

 heads of massive corals ; they are small Mseandrinas and Astraeans, to- 

 gether with an abundant growth of Sargassum, Algae, and Sponges. The 

 Sponges are more abundant on the connecting ledges, if I may so call 

 the patches extending from the north side of the main channel towards 

 the flats, than they are upon the outer ledge flats. 



As far as we can judge from such an examination as can be made in 

 crossing the reef flats from the inner waters to the open sea, in the sec- 

 tions across the reef at Hoglish Cut, across the Western Ledge Flats at 

 Little Bar and opposite the west end of Long Bar off the Chub Heads, 

 across Chub Cut, across the Blue Cuts, across at the Northwestern Ledge 

 Flats, across at the North Rock, Northeast Flats, Mills Breaker Passage, 

 and the main channel, all the " coral heads " or patches seem to be 

 growing on the tops of pinnacles of aeolian rocks, or of flat ledges, or of 

 mushroom-shaped tables, or of large irregularly shaped ledges rising 

 sometimes gradually in irregular shelving strata, or in nearly perpen- 

 dicular steps, from six or seven fathoms of water to near the surface. 



Passing through Chub Cut to the outside of the reef, we find in four 

 to five fathoms large Maeandrinas, Astraeans, and fine Gorgonians, together 

 with the usual accompaniment of Millepores, Sargassum, Corallines, and 

 other Algae. As we pass into deeper water the massive corals become 

 smaller; in seven fathoms they are quite small and not numerous, and the 

 whole bottom becomes thickly covered with Gorgonians, Corallines, and 

 Sargassum. 



An examination of the charts of the Bermudas will show many places 



