242 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



Blue Cuts, and Chub Cut, as well as between Long Bar and the West 

 End Ledge Flats. There are outside of the reefs many areas of rocky 

 bottom, marked r on the chart, the remnants probably of extensive 

 seolian ledges. 



Nowhere do we find more fantastic shapes in the pinnacles remain- 

 ing on some of the ledges than those which are seen to the south of 

 Nonesuch Island, and extend to the eastward toward St. David Head. 

 The islands pass into pinnacles, into ledges, and finally into boilers, in 

 regular succession, and in proportion to the exposed condition of their 

 position. Similarly eroded pinnacles are also seen on a smaller scale, 

 but of fully as fantastic shapes, in St. George Harbor, in Mullet Bay, 

 and on the south side of the causeway on the western side of Castle 

 Harbor. 



The patches outside of the reef off the south shore can be clearly seen 

 extending a short distance to sea, separated by irregular white patches of 

 sand. The inner ledges, forming the patches between the outer reef and 

 the shore, are most capriciously distributed. Outside of the reef off the 

 south shore the corals do not seem to thrive, and the broken ground is 

 comparatively barren, though we find an occasional patch where Gor- 

 gonians, Algae, and massive corals are more abundant. The coral 

 growth is more that of the broken ground than of the reef flat ledges 

 or of the connecting patches. 



Heilprin has noted the great importance which the Millepores take in 

 the composition of the bank sand bottom. On the south shore, where 

 Serpulae are so abundant, the fragments of their pinkish shining tubes 

 can readily be distinguished in the coarser fragments of the sand thrown 

 up on the many beaches along the shore. While in the Bahamas I was 

 struck by the importance of the Millepores in the economy of the reefs. 

 They seem to be far more abundant there than upon the Florida reefs, 

 where the Madrepores take an extraordinary development, while they 

 are absent in the Bermudas. 



The south reef extends at a distance from the coast of about one 

 thousand to fifteen hundred feet throughout its length from the en- 

 trance to St. George Harbor to the eastern side of Hogfish Cut. It 

 has nothing to do with a barrier reef as such. It is a barrier ledge 

 of seolian rocks derived from the old shore line, and not a barrier 

 reef formed by corals, as Heilprin would lead us to suppose. The 

 description which he gives of the work of destruction going on upon 

 the barrier reef which skirts the southern coast is somewhat unfor- 

 tunate, as the material of which he speaks as " blocks of coral and 



