1881. ] Mya arenaria in San Francisco Bay. 365 
duced from the waters of the Asiatic shores of the North Pacific 
or from the American shores of the North Atlantic? If artificially 
introduced, of which there can be no doubt—from which direc- 
tion does the extent and character of the traffic of our commercial 
intercourse make it most probable that the species came or was 
brought? By water on the steamships from Japan, or by railroad 
three thousand miles overland from the Atlantic seaboard ? 
With the completion and operation of the trans-continental 
railroad, our oyster men, many of whom have a large capital in- 
vested in the business, commenced the importation of small 
oysters (O. virginica) from the Atlantic side, by the car load, for 
planting in San Francisco bay, where ina season or so they attain 
a merchantable size, growing exceedingly fat; as yet, efforts to 
Propagate them have not been successful; but the importation 
still continues as before, the profit to the oyster planter being sim- 
ply through increase in size and not from multiplication of num- 
bers by propagation. 
There is no similar traffic with Japan, and it is hardly possible 
that the fry of Mya arenaria, if it did adhere to the bottom of the 
steamers in Japanese parts would be able to hold on for so longa 
time or for so great a distance with the friction of the water 
against the bottom of the steamer constantly operating to sweep 
it off. 
Native oysters are also imported from various points in Wash- 
ington Territory, and planted in the bay, but we have no knowl- 
edge of the Mya existing at any point in the region from whence 
these latter oysters are brought. 
In the presence of the fact of the rapid increase of this. truly 
excellent edible, next to the oyster the most valuable either as 
human food or fish bait, of any of this class of food, and the infer- 
€nce from its spreading so readily in San Francisco bay, that other 
places along the coast might prove equally congenial to it, it 
would be a wise, public spirited act if the captains of our coasting 
vessels would take the trouble and incur the slight expense attend- 
ing the planting of this clam at such points as their vessels touch 
at in the ordinary course of business. 
Since the manuscript of the foregoing matter was sent to the 
Naturauisr, I have received specimens of Mya arenaria from my 
end, Dr. C. L. Anderson, of Santa Cruz, for identification. 
Santa Cruz is on the coast at the northerly end of Monterey bay, 
