oyster from San Diego, about two inches long, narrow and moderately widening, - 
ghtly sigmoid in form, its margins simple and the extremity somewhat truncate and undulate 
or ' dentate, with four or five radiating grooves ; shell compact, upper valve purplish. It occurs 
jn clusters intimately grouped, much like the parasitic oysters of Carolina, but more elongate, 
less digitate at the end, less cavernous under the beak, and less black within, 
3 z 
v! p* Sr 
fsa AN 
T E $: jm. 
i: E d Li 
ET 
