332 
been submerged by the tide. They had migrated to the outer Spartina 
areas during the low tide period. They are very abundant in the higher 
marsh «areas. 
It would be extremely interesting to know something of the life his- 
tories of the insects of the between tides zone, especially as to where 
they spend the winter, as to the methods of egg laying, and as to the 
types of larvee. 
CONCLUSION. 
In almost every insect of the between tides zone there appears to 
be some peculiar protective feature; as, unique instincts, especially 
adapted external parts, or a greater resistivity to drowning. 
Unique instincts, to prevent themselves from being washed away by 
the tides, are well shown in the tenacious clinging to the blades of Spar- 
tina by the Grammonata trivittata, Megamelus marginatus, and Clubonia 
sp (7). Another feature of the same type is the crawling of the Bembidium 
constructum under the gravel. That the environment has undoubtedly led 
to the formation of these instincts is illustrated by the comparison of the 
habits, when submerged, of the spiders of the Spartina area with those 
found higher on the marsh. Another instinct which serves the same pur- 
pose is the venturing forth for food by the Salda only on sunny days at 
low tide. The Grammonata trivittata and Megamelus marginatus un- 
doubtedly rest head downward on the Spartina grass to prevent themselves 
from being caught unawares by the rising tide. 
Inconspicuousness as a means of protection from aquatic enemies is 
shown by the swimming of the Salda to the Fucus thallus when disturbed 
during high tide. Other reactions serving the same purpose, are illus- 
trated by the resemblance of Megamelus toe the Spartina blade, the crawl- 
ing the Grammonata into the pits at the junction of blade and stem, and 
the living of the beetles in burrows. 
That one of the factors which determines the surviving species in a 
between tides zone is an ability to resist drowning, is shown by a com- 
parison of the resistivity of Grammonata and Clubonia with that of other 
spiders. 
A modification of the external features as an adaptation, is shown in 
the greatly modified legs of the Megamelus marginatus and in the short, 
stiff hair of the Grammoniata trivittata. The legs of Lycosa communis 
are not essentially different from those of other Lycos; yet their long, 
