AGASSIZ: THE FLORIDA ELEVATED EEEF. 



49 



the general line of the Keys. 1 These passages give exit to the mass 

 of material disintegrated from the small keys of the group. The bot- 

 tom of the interior is naturally barren, being covered with a sticky marl, 

 upon which grow mangroves and on which we find an occasional hole of 

 Calianassa, a Limulas, or a skate swimming about, and Thalassia growing 

 plentifully upon parts of the bottom. 



Scale 



May not the keys of the bank to the eastward of the Marquesas be 

 merely the remains of similarly disintegrated land, the greater part of 

 which has been eroded, leaving only the scattered keys between the 

 Marquesas and the west side of Key West Harbor ? (See Coast Survey 

 Chart, Xo. 169.) 



1 A. Agassiz, " The Tortugas and Florida Reefs," Mem. Amer. Acad., 1883, Vol. 

 XI. p. 118, Plate V. See also "Three Cruises of the Blake," Bull. Mus.'Comp. 

 Zoiil., Vol. XIV. p. 172, Fig. 44. 



