SALT AND FRESH-WATER CLAMS. 21° 
As I have called the attention of the fishermen in this 
vicinity to the rarity of this fish, I shall probably get speci- 
mens that would otherwise have been thrown away, and 
hope to gain farther information respecting this uncommon 
species. 

SALT AND FRESH-WATER CLAMS. 
: BY EDWARD S. MORSE. 
WE choose these two animals for description since they 
are accessible to all. The inland student may rake from the 
pond or river the fresh-water clam, or mussel, in quantities, 
while the sea-side student has only to step into the market 
and order the salt-water clam by the bushel. 
In presenting such descriptions for study, it is always best 
to cite as examples those forms which are most abundant, so 
that whatever statements are made can be quickly verified 
by an examination of the object described. A general 
knowledge once attained of the common animals, prepares 
one to enter farther into the study of zoólogy. and enables 
him, through the facts already garnered, to use his informa- 
tion in the proseeution of new investigations. We commence, 
then, with the description of an animal, about which little has 
been said except in books professedly scientific; an animal, 
however, long and well known from the cheap and excellent 
food it affords, and from its no less importance in providing 
bait for our fishing fleets. 
That the daintiness of the clam for food was known to the 
aborigines of this country, is well attested by the huge piles 
of broken clam shells scattered along our eastern coast, 
and now buried beneath a foot or more of soil. Mingled 
with these piles the arehzologist reaps a rich harvest of In- 
dian relics, such as implements made of bone, fragments 
of pottery, ete.* These are the only evidences of by-gone 

-*In the NATURALIST, Vol. I, p. 561, Prof. J. hd rg describes the contents of some 
of these beds, with illustrations of the various relics 
