MUSEUM OF COMPARATIVE ZOOLOGY. 157 



NOTE. 



The discovery by Professor Shaler of the northern extension of the great 

 Florida Reef beyond Key Biscayne, on the east shore of the southern extremity 

 of Florida, as far as Jupiter Inlet, throws a good deal of light on the probable 

 mode of formation of the Everglades. An examination of the map of South- 

 ern Florida in the Memoirs of the Museum of Comparative Zoology, Vol. VII., 

 No. 1, Plate XXIII., or of the map (Plate VI.) in my Memoir on the Tortugas, 

 Memoirs of the American Academy, Vol. XI., 1SS3, or in the "Three Cruises 

 of the Blake," page 52, shows that in all probability the process of land-mak- 

 ing is simply more advanced in the Everglades than in the triangular stretch 

 of mud flats extending westward from the northern keys of Florida beyond 

 Cape Sable, and from that base in a general southwesterly direction to the Mar- 

 quesas. The presence of fossil reefs more or less concentric with the line of 

 keys induced Professor Agassiz,^ in his Report on the Florida Reefs, to look 

 upon the Everglades as holding to those reefs very much the same relation 

 which the mud ilats to the west of the main line of reefs hold to the latter. 



Geologists 2 have, as a general rule, been opposed to this view, but they have 

 only examined the mainland nortli of the Everglades, and no geologist has as 

 yet penetrated farther into the Everglades than Professor Agassiz and his party. 

 A careful examination of the Everglades alone can determine whether their 

 fossil reefs are built upon a base consisting of the rocks which have been ex- 

 amined by Tuomey and others at Tampa Bay and Charlotte Harbor, or whether 



1 Annual Keport of the Superintenaent of the Coast Survey, 1851. Report on 

 tlie Florida Reefs, by Louis Agassiz. Memoirs of the Museum of Comparative 

 Zoology, Vol. VII. No. 1, 1880, pp. 31, 57. 



2 Report of Buckingham Smith ou the Drainage of the Everglades. Heilprin, 

 Trans. Wagner Free Institute of Science, Vol. I., May, 1887. Heilprin's explora- 

 tions were limited to the portions of the west coast of Florida included between 

 Cedar Keys and Punta Rassa, and did not touch the Everglade district or the great 

 Florida Reef. Likewise, the earlier researches of Conrad and Tuomey, and the .sub- 

 sequent ones of Smith, DalJ, and others, have all stopped short at the Everglades, 

 and the structure of the northern extremity of Florida has nothing whatever to do 

 with the formation of the coral reefs from Key Biscayne south. How far north this 

 reef structure extends is another point, and Shaler's interesting discovery goes far 

 towards giving us a clue to the mode of formation of the Everglades. That the 

 northern part of the peninsula of Florida is not made up of concentric coral reefs is 

 now very clearly demonstrated by geological and palaeontological evidence. What 

 is the southern extension of the formations which extend to the northern edge of 

 the Everglades, no one knows as yet. 



