Proceedings Am. Philos. Soc. Vol. LV. 



Plate XII 



Fig. I. Salt marsh pool at Nantucket, Massachusetts, August, 1914, sur- 

 rounded in part by tall salt grass, Spartina glabra. 



Fig. 2. Dry salt marsh pool at Cold Spring Harl)or, Long Island, with 

 dry crusts of alg;e, July, 1914. 



