DEPARTMENT OF MARINE BIOLOGY.^ 



In accordance with authority received from the Board of Trustees of the 

 Institution, special investigations at the Tortugas Laboratory have been con- 

 tinued, reports of which will be found in the following pages. Mr. John W. 

 Mills, chief engineer, has remained in charge of all equipment and has super- 

 intended necessary repairs to the Laboratory buildings; he also aided in col- 

 lecting material for laboratory study and in procuring supplies. A bronze 

 tablet, executed by Mrs. Alfred G. Mayor, was erected to the memory of 

 Dr. Mayor on the site of his former activities. 



The following investigators studied under the auspices of the Department 

 during the past year: 



Dr. Paul Bartsch, Porto Rico, Bahamas, and Tortugas, May and August. Continuation 

 of experiments with cerions. 



Dr. H. E. Crampton, island of Moorea, South Pacific. Field investigations on the varia- 

 tion, distribution, and evolution of species of the genus Partula. 



Dr. C. B. Lipman. Study of sea-water of the Pacific Ocean. 



Dr. William H. Longley, Tortugas, June 6 to August 25. Submarine color photography 

 and habits of Tortugas fishes. 



Dr. Asa A. Schaeffer, Tortugas, June 6 to July 15. Marine amebas. 



Dr. D. H. Tennent, Misaki Laboratory, Japan, May to September. Continuation of inves- 

 tigations on echinoderms. 



Dr. W. A. Setchell. Report on general relations of flora of Tahiti. 



Dr. T. Wayland Vaughan. Reports on corals collected in the Samoan Islands and on fossil 

 mollusks of the Bowden marl of Jamaica. (J. Edward HofTmeister and W. P. 

 Woodring.) 



Mr. Mills rendered assistance in the collection of Valonia from the sea-water 

 in the vicinity of Miami for use in investigations undertaken at the Miami 

 Aquarium by Mrs. M. M. Brooks, of the U. S. Public Health Service; he also 

 collected plankton for a period of three months for the use of Dr. Fox, of 

 Gonville and Caius College, Cambridge, England. 



REPORTS OF INVESTIGATORS. 

 Breeding Experiments with Cerions, by Paul Bartsch. 



In order to add two new elements to the cerion breeding experiments con- 

 ducted on the Florida Keys, it became necessary to make a trip to Porto 

 Rico, where a new color-banded form was discovered some time ago by an 

 expedition of the New York Academy of Sciences. Dr. Bartsch secured 

 passage on the Navy transport Henderson on May 2 for San Juan, Porto Rico. 

 From there he went to Guanica Bay, where a week was spent in intensive 

 collecting about the entrance to Guanica Harbor. Here a large amount of 

 cerion material was secured. The return trip from Porto Rico was made 

 on the U. S. Navy transport Kittery. 



A second expedition in search of a spirally striated cerion, reported from the 

 southeastern Bahama Islands, was undertaken on August 9, when Dr. 

 Bartsch left on the Army transport St. Mihiel, from the Brooklyn army 

 base, for San Salvador, Bahamas. Through the kindness of the Army and 

 Navy, a landing was made at Cockburn Town, and two weeks were spent in 

 intensive collecting on this island. Unfortunately, Dr. Bartsch's efforts 

 determined the fact that the spirally striated cerion does not occur on San 



^ Situated at Tortugas, Florida. 



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