THE Bulletin of the Museum of Comparative Zoology at Harvard College, published in June, contains three letters from Prof. Alexander Agassiz to the Hon. Marshall McDonald, United States Commissioner 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 oCalifornia. The operations, which were in charge of Prof. Agassiz, were carried on by the U.S. Fish Commission steamer Albatross, Lieutenant Commander Z. L. Tanner, U.S.N., commanding.