SHALLOW-WATER FORAMINIFERA OF THE 

 TORTUGAS REGION. 



Bv Joseph AuausTiNE Cushman. 



INTRODUCTION. 



The present paper gives the results of a study of collections made 

 in the waters about the Tortugas Laboratory of the Carnegie Insti- 

 tution of Washington. The Dry Tortugas are a group of small keys 

 well out from the Florida Coast; both in the lagoon which is formed 

 by the group of islands and in the waters outside they afford a range 

 of conditions of much interest. In general, the range of temperature 

 was not great, due to the proximity of the mass of warm Gulf 

 Stream water which sweeps by to the southerly side of the group. 

 Within the limited area, however, varied ecological conditions were 

 found which will be later noted and which seem to have a direct 

 influence on the presence or absence of certain species in those 

 places. 



Collecting was done largely from the boats, the most satisfactory 

 method that used with the Darwin. This is equipped with glass- 

 bottomed wells, and it was possible in collecting on the reef areas to 

 let the snapper down to within a short distance of the bottom, 

 where in the clear water it could be easily seen at several fathoms; 

 then, on passing over a suitable spot, free from corals, the gear was 

 allowed to run and samples of the bottom were obtained before 

 coral heads again came in the way. Collecting in the moat at 

 Fort Jefferson on Garden Key and in shallow water on Long Ke}', 

 as well as on the reefs and flats, was done by hand. 



An opportunity was afforded of studying living forms. Results of 

 these studies are also given here, some of them being of special 

 interest as throwing hght upon disputed problems. 



I gratefully acknowledge the many courtesies shown me by 

 Dr. Alfred G. Mayor, Director of the Tortugas Laboratory, in the 

 carrying on of the work while at the Tortugas, and to the Carnegie 

 Institution of Washington for the services of Mr. J. Henry Blake, 

 who has so carefully drawn the figures on the plates in this report. 

 The text-figures I have drawn myself. 



The Tortugas region presents an ideal spot for studying the 

 shallow-water tropical Foraminifera of this particular region. It is 

 far removed from influence of shore conditions; the water is at all 

 times warm and pure, so that ecological conditions that are present 

 are constant. The shallow-water Foraminifera of the Gulf of Mexico 



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