Edible Mollusca of the Oregon Coast.’ 
By CHarRLES Howarp EDMONDSON. 
IN'TRODUCTION. 
The Oregon coast from the mouth of the Columbia River to 
California presents an exceedingly varied contour. Low, flat, sandy 
beaches alternate with rugged headlands while the shore line is 
indented by numerous bays and inlets of greater or less extent. A 
number of rivers of considerable size, draining the Coast Range 
Mountains, flow into the Pacific within the boundaries of the state, 
their waters influenced by the daily tides for several miles from the 
ocean. Most of them expand into broad, shallow bays near their 
mouths and some of them are characterized by extensive mud flats 
on one or both siees of the channel which make ideal. habitats for 
numerous forms of marine or brackish water organisms. In many 
places the coast is paralleled by fringing chains of rocks representing 
remnants of a former shore line, now serving as footholds for such 
fixed organisms as have become adapted to the full sweep of the 
waves. 
As the physical features of any coast line determine the types 
of animals and plants that are distributed along it, so the organisms 
of the open beaches differ considerably from those found in the pro- 
tected bays and mouths of rivers or along the rocky shores. 
The habitat conditions in the tidal zone along the northwest 
coast are such that numerous lamellibranchs have become established 
and are maintaining themselves more or less successfully. Of this 
number there are about a dozen, besides the western oyster,? Ostrea 
lurida Carpenter, which have already been recognized, to some 
extent at least, as fit for human food. 
The following list of clams and mussels represents the bivalves, 
exclusive of the oyster, of the Oregon coast which have entered into 
the food economy of the people of the state in some slight degree: 
Siliqua patula Dixon, commonly known as the “razor clam’; Mya 
arenaria Linnaeus, the “long neck clam” or “eastern mud clam”’; 
Paphia staminea (Conrad), called the “little neck clam” or “hard 
clam”; Schizothaerus nuttalli Conrad, locally known as the ‘“Wash- 
‘The investigations recorded in this paper were conducted while the writer was a 
member of the teaching staff of the University of Oregon. 
* For a discussion of the oyster see page 23 of this paper. 
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