86 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



For the first i8 inches the turf formed an exclusive and very 

 tough mat, just beneath which were found a large quantity of 

 clam shells, emphatically not a kitchen midden. These have 

 been identified as Venus mercenaria which is "common in shallow 

 water on muddy bottoms in the bays and estuaries about Long 

 Island."^ Below the clam shells apparently pure beach sand and 

 gravel were found with very few traces of vegetable remains. 

 Here the inference that we have to do merely with a recently 

 sunken beach whose clam strewn shore has been covered by 

 "salt hay" seems clear enough. 



III. Within one half mile of the edge of the cedar swamp and 

 about 100 feet from the tidal stream, which seems from the 

 general configuration of the land to have always been the natural 

 drainage of the stream now flowing through* the cedar swamp. 

 The surface of the ground where the pit was dug was covered prin- 

 cipally by the following: 



Spar Una patens A triplex hast at a 



Distichlis spicata Agalinis maritima 



Plantago maritima Limonitim carolinianum 



Sahbatia stellaris Solidago sempervirens 



For the first i8 inches, as in the other pits, the turf was nearly 

 exclusive, but below we find an entirely new condition indicated. 

 Large quantities of twigs, sticks, wood, bark, leaves, half a hickory 

 nut, and other remains indicating vegetation decidedly not of 

 the salt-marsh type were abundant, mixed with fine clean sand 

 and gravel. There is an almost startling change between the 

 salt marsh surface and this evidently upland vegetation, now 

 buried. None of the remains could be definitely identified as 

 those of Chamaecyparis. 



IV. Surface covering the same as at the third pit, except for the 

 addition of Sangtiisorba canadensis and a few other swamp plants. 

 This station is just outside the zone of dead cedar trees (see 

 PLATE lo) and the character of the remains practically the same as 

 in III, except that definitely idcntilial:)le Chamaecyparis remains 

 are fairly common. 



What can all this point to ])iit the gradual dying out of the cedar 

 and its replacement by salt marsh? The phenomenon has been 

 mentioned so many times before that there seems hardly any 



' Kindly iclL-ntificd for mc by Mr. G. P. Engelhardt of the Brooklyn Musciiiii. 



