252 bulletin: museum of comparative zoology. 



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

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

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

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

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

 beloniiini;- 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 b^' the coral growth. But both on the north and on 

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

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

 \vith tlie sill ire 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; the}' are small Maeandrinas and Astiaeans, to- 

 gether with an abundant growth of Sai'gassum, Algje, 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 tlicy are upon tlie outer ledge flats. 



As far as wo can judge from sucli an examination as can be made in 

 crossing the reef flats from tiie inner waters to tiie ()])en sea, in the sec- 

 tions across tlie reef at Hogfish 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 seolian 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, fVom 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 fithoms large Mteandrinas, Astra^ans, and fine Gorgoiiians, together 

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

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

 smaller ; in seven f itlioms they are quite small and not inimerous, and the 

 whole lutttom becomes thickly covered witli (;oi-gouians, Corallines, and 

 Sargassum. 



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



