12 PAPERS FROM THE DEPARTMENT OF MARINE BIOLOGY. 



ment and in ascertaining by extensive field study the exact relations the 

 reefs, both fossil and Recent, in Florida, the Bahamas, the West Indies, and 

 Central America, bear to the geologic history of the areas in which they occur. 

 In his article, which follows this paper, he gives a list of his publications; 

 references to some are in the footnote' below. He has greatly multiplied 

 the evidence in favor of recent submergence in the coral-reef areas in the 

 western Atlantic, the Gulf of Mexico, and the Caribbean Sea, and has shown 

 that the living offshore reefs have formed either during or after submergence 

 and are growing on submerged basement platforms where conditions are 

 favorable for the life of reef-forming corals. The platforms continue beyond 

 the northern or southern limits of the reefs and their existence is in no wise 

 dependent upon the presence of reefs. Vaughan's explanation is, therefore, 

 similar to that announced by A. Agassiz, except that he takes into account 

 geologically Recent submergence. The explanation of Andrews for the Great 

 Barrier Reef of Australia and that of Vaughan for the Floridian, West Indian, 

 and Central American reefs are identical. 



Vaughan has also shown that the Great Florida Plateau has existed as 

 a plateau since at least late Eocene time; and that some of the West Indian 

 platforms are about as old. As these platforms existed previous to Pleisto- 

 cene time they could not have been formed by marine planation during 

 Pleistocene glaciation. Whatever be the cause of shift in position of strand- 

 line, off-shore reefs form on submarine flats during or after rise in sea-level, 

 provided the rate of submergence be not too rapid, and the amount be not 

 too great. This explanation applies to the fossil reefs of Florida and the 

 West Indies as well as to the reefs living today. He has recently pointed 

 out in the Virgin and northern Leeward Islands and off the shores of Central 

 America certain submarine terrace flats, one at a depth of about 17 to 20 

 fathoms, another at a depth of about 26 to 30 fathoms, the deeper flat being 

 separated from the shallower by an escarpment. These relations accord 

 with the demands of the Glacial control theory as expounded by Daly. 



It is obvious that the views of Andrews, Daly, and Vaughan' have much 

 in common, but are in marked contrast with those of Murray^ and of Agassiz, 

 who maintain that lagoons of barrier reefs and atolls are largely due to solu- 

 tion, or of W. M. Davis^ and P. Marshall, who support the Darwinian subsi- 

 dence theory of reef formation, while Daly, Wood Jones, Hedley and Taylor, 

 and Vaughan deny the efficacy of solution, and Gardiner and Guppy consider 

 solution to be an important factor. Clearly the subject of the formation 

 of barrier reefs and atolls is far from being settled in the minds of its students. 



'Vaughan, T. W., 1914, Bull. Geol. Soc. Amer., vol. 26, p. 58; also 1914, Bull. Amer. Geog. Soc, vol. 46, 

 p. 426; and 1915, Abstracts of Papers, Geol. Soc. Amer., 28tli Annual Meeting, p. 19. 



'Murray, J., 1880, Structure and Origin of Coral Reefs and Islands, Proc. Roy. Soc. Edinburgh, vol. 10, p. 505. 



'Davis, W. M., 1915, Amer. Jour. Sci., vol. 40, pp. 223-271, 9 figs.; also Scientific Monthly, 1916, vol. 2, 

 PP- 3'3~333; 479-50'; 557-572; also Proc. National Acad. Sci., vol. i, pp. 146-152; vol. 2, pp 284-288; 466-475. 



•Marshall, P., 1912, Australasian Association for Advancement of Science, vol. 13, pp. 140-145, pis. lo, 11. 



