36 THE SHELL-FISH OF THE COAST. 
purple margin the Indians cut their purple wam- 
pum (shell-money), the white wampum being ob- 
tained from the columellar axis of the pear-conch 
or winkle (Fulgur). 
SAND-CLAM (Mya arenaria). 
the waste products. 
The word ‘ quahog’ appears 
to be a corruption of the plural 
Poquahock, or, as it is written, 
‘ Poquahauges.’ 
Careful observers of the 
ocean beach will have noticed 
from time to time little jets of 
water issuing from scattered 
holes in the sand; or fre- 
quently the shallow waters of 
pools may be observed twirled 
round into eddies by suction 
and ejection currents coming 
from below. The author of this 
play of water is the sand-clam 
(Mya arenaria), which lies 
buried a few inches below the 
surface, whence it communi- 
cates with the outer world by 
means of its extended siphon. 
Through this siphon, which is 
in reality a double tube, water- 
currents are passing both in- 
ward and outward, bringing 
necessaries to the secluded 
creature, and carrying from it 
The depth to which the animal 
burrows will depend closely upon the length of its 
respiratory siphon. 
Although it measures but a 
