1915] ROBERTS—BEACH PLANTS 407 
Beach, Nobska Beach, Lackey’s Bay, Tarpaulin Cove, Cuttyhunk, 
and Quicks Hole. The sea cliff without Zostera marina was found 
at Nobska Cliff and Falmouth Cliff. The sea cliff with Zostera 
marina was found at Lackey’s Bay (inside), Ram Island, Cutty- 
hunk Pond, and Deer Island. 
The following 9 plants were the characteristic succulents found 
on the middle beach: Atriplex arenaria, Salsola Kali, Chenopodium 
rubrum, Arenaria peploides, Cakile edentula, Artemisia Stelleriana, 
Solidago sempervirens, Euphorbia polygonifolia, and Lathyrus 
maritimus; while Ammophila arenaria has been included in the 
chart as a tenant of the middle beach because it plays a part in the 
zonal distribution of some of the succulents. SNow (7) speaks of 
the upper part of the middle beach as the low Ammophila zone, 
thus subdividing the middle beach into the succulent zone (lower 
half) and low Ammophila (upper half). The drift spoken of as 
limiting the middle beach at the front is the daily tide line. The 
spring tide line seems to sweep back the daily tide débris, together 
with its own gatherings, to a line back of the daily tide. This 
irregular line of débris at the front of the lower middle beach, 
determined by the spring tide, marks the extent forward of the 
succulent zone, while the summer storm tide line marks the begin- 
ning of what I term the transitional zone, corresponding, I believe, 
to the low Ammo phila zone of SNow. Succulents and Ammophila 
tenant the region together, with the Ammophila dominating just 
back of the winter storm tide line or on the upper beach, the term 
Ammophila being thus used to apply to the upper beach. The 
plants exclusive of Ammophila arenaria were found in the order 
given as outpost plants as shown on the chart. 
At Chappaquoit Point all the 1o characteristic plants were 
found. Atriplex arenaria was the forerunner, as it always is when 
present. BERGEN (1) states that Salsola Kali is the most tolerant 
of the plants he observed. It ranges here from Artemisia Stelle- 
riana to just back of Atriplex arenaria, with some plants occasionally 
at the top of the dune. Chenopodium rubrum is confined to a 
region just back of Salsola Kali. Arenaria peploides grows in 
masses and monopolizes a wide zone. Cakile edentula grows more 
in bunches and is closely associated with Artemisia Stelleriana, 
