= 
. 
REPORT OF COMMISSIONER OF FISH AND FISHERIES. 109 
the steamer proceeded first to the vicinity of Cape San Francisco, 
thence to the Galapagos Islands, and from there to Acapulco. Subse- 
quently, dredgings were made from off Cape Corrientes to Guayias, in 
the Gulf of California, The greatest depth of water explored was 2,232 
fathoms. Short stops were also made at the different islands lying in | 
the course of the expedition, for the purpose of studying the land and 
shallow-water animals and plants. While it was observed that the 
marine fauna of this region is not so rich as that occupying the corre- 
sponding waters off the east side of the continent, very large collections 
were secured, and the general results obtained are of great importance. 
Soon after this material was received in Washington the different 
groups were carefully sorted out, and the greater number have already 
been assigned to specialists for Study under the direction of Professor 
Agassiz. 
One of the most important outcomes of the expedition has been the 
determination by Prof. Agassiz, through the instrumentality of the 
intermediate towing net, of the vertical distribution of the surface 
pelagic fauna, which he considers to descend only to a depth of about 
200 fathoms. Some forms among the bottom animals may work up a 
distance of several fathoms, but between these levels in the open sea 
he finds no evidences of life. Regarding this subject there are still 
some differences of opinion among explorers, and further investigations 
will be awaited with much interest. As a solution of the problem may 
have some bearing upon the study of the habits of the Atlantic coast 
mackerel during its migrations in the deeper water, the practical 
importance of continuing the experiments can readily be appreciated. 
Detailed accounts of this investigation will be found in the report 
of Capt. Tanner, contained in the appendix to this volume, and in the 
publications of the Museum of Comparative Zoology, Cambridge, 
Mass,* 
“Three letters from Alexander Agassiz to the Hon. Marshall MeDonald, U.S. Com- 
missioner of Fish and Fisheries, on the dredging operations off the west coast of 
Central America to the Galapagos, to the west coast of Mexico, and in the Gulf of 
California, in charge of Alexander Agassiz, carried on by the U.S. Fish Commission 
steamer Albatross, Lieut. Commander Z. L. Tanner, U.S.N., commanding. Bull. Mus. 
Comp. Zo61., xx1, No. 4, pp. 185-200, 1891. 
General sketch of the expedition of the Albatross, from February to May, 1891. 
By Alexander Agassiz. Bull. Mus. Comp. Zodl., xxut, No. 1, pp. 1-89, plates 1-22, in- 
cluding a detailed chart of the explorations, 1892. 
Calamocrinus diomeda, a new stalked crinoid. By Alexander Agassiz. Mem. Mus. 
Comp. Zo6l., xvi1, No, 2, 96 pp., 32 plates, 1892. 
