MUSSEES AND PECTENS 31 
The principal species on our 
coast is named Mytilus califor- 
nianus, Conr., the California 
Mussel. A good picture is given 
in Figure 14. This species can 
: easily be distinguished by the 
\s ww conspicuous ribs, which are 
Sj never wholly absent, particu- 
larly on the newest parts of the 
shell. The beaks of old speci- 
mens are apt to be much eroded, 
but the growing edge is protect- 
ed by a glossy epidermis. The 
general color of the shell is 
purple, though the thicker 
parts of it are white, and some- 
times there are streaks of 
brown, which harmonize re- 
markably well with the purple. Occasionally a very 
large and perfect specimen is polished on a lapi- 
dary’s wheel, and the result is remarkably pretty. 
But far more often we see nature’s method of 
bringing out the colors. If you find a little beach 
near a mussel ledge you will notice that the sand 
contains unnumbered bits of blue and white and 
brown, all bright and polished and forming the 
most lovely bed of gaily colored gravel. If you 
examine the pieces you will find that most of them 
are nothing but broken mussel shell, and you will 
admire the bright colors which blend so_ per- 
feetly. And while speaking of colors, let me ask 
you to observe the combinations all along the rim 
a 
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Vous 
Mii, 
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