98 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
iuto the level low lauds which here front the coast. The oysters were here found 
under the same conditions as those in the upper lagoon, growing along the shores, 
or forming hummocky islands dotting the shallower portions of the lagoon. 
I was unable to learn that any fresh water flowed directly into either of the 
lagoons ; there was, however, much difference in the amount of fresh water which 
they contained, the upper lagoon having almost the same density as sea water, its 
specific gravity being 1.026508. The lower lagoon contained much more fresh water, 
the specific gravity being 1.023808. Whether this was owing to the state of the tide, 
different in the two cases, or to the proximity of the river to the lower lagoon, I was 
unable to decide. 
The Yaqui Eiver is a deep swift stream, reaching the Gulf through a single well- 
defined channel, which widens but little towards its mouth. Even during the dry 
season it discharges a large volume of water iuto the Gulf, the specific gravity at our 
anchorage, 3 miles distant from the shore (1.006808), showing the water to be only 
slightly brackish. This volume of fresh water may spread far enough along the coast 
to be backed by the tide into the lower lagoon. No oysters were found in the river, 
which was explored for a distance of about 4 miles. 
The Gulf oysters we found to be large, fat, and of excellent flavor, being uniformly 
pronounced by our ship’s company to be equal to the best Eastern product. They are 
now used only to supply the very limited demand at Guaymas. The Indians gather 
them by the boat-load, selecting only the larger ones, carry them to Guaymas, and 
preserve them until wanted by depositing them in the bay. We were informed that 
the oysters d<^ceriorated after being kept in the bay four or five weeks, but this was 
denied by others. 
As to the propriety of attempting to transplant the oysters to the coast of Cali- 
fornia, I am in some doubt. The fact that almost the entire littoral fauna of the Gulf 
differs from that found to the northward seems to indicate the existence of dissimilar 
conditions which would militate against success. The temperature in the lagoons 
along the Gulf during the winter and early spring is about 70° Fahr., as compared with 
60° in the bays of southern California. And during the rainy season in the Gulf, the 
amount of fresh water found in those shallow lagoons must be much greater than was 
found by us in the dry season, and probably more than could be looked for at any 
time in southern California. 
