Proceedings Am. Philos. Soc. Vol. LII. No. 21 1 



Plate XXI 



M.WGROVE Roots, Silting of River Mouths. 



Figs, a and c. Mangrove roots at low tide, Tutoya, Maranhao. Photo- 

 graphs by G. A. Waring, 191 1. 



Fig. b. Mangrove roots at the mouth of Rio Pirangy, Rio Grande do Norte. 

 Photograph by E. Leib, 191 1. 



