THE BRYOZOA OF THE TORTUGAS ISLANDS, FLORIDA. 



By Raymond C. Osburn. 



In the summer of 1908 the writer had the privilege of spending the 

 month of June at the Carnegie Institution Laboratory for Marine Biology, 

 located on Loggerhead Key of the Tortugas Islands. Owing to the short 

 time at my disposal the entire period was devoted to a close search for the 

 bryozoa inhabiting the shallow waters about the reefs, on the piles of the 

 old government dock on Garden Key, in the moat of old Fort Jefferson 

 on the same key, and in dredging the shallow waters about the islands 

 down to 22 fathoms. For much of the work a skiff or a small launch 

 was used, and for the deeper dredging (10 to 22 fathoms) the schooner 

 Physalia was employed. The Tortugas Islands are islets of a coral atoll 

 and in the diversified bottom afforded by such a region a rather abundant 

 bryozoa fauna was found. 



Comparatively little work has been done on the bryozoa of the Florida 

 and West Indian regions. Smitt's papers on the Florida bryozoa (1872-73) 

 deal with 87 species collected by Count L. F. de Pourtales and afford the 

 only extended record of the bryozoa of this region. Pourtales (1867), in 

 a paper entitled "Distribution of the Fauna of the Gulf Stream at Great 

 Depths," listed and described as new 7 species of bryozoa, 2 of which have 

 been proved to be synonyms. Verrill, in his Bermuda papers, has listed 21 

 species from the Bermuda Islands. Levinsen, in his important work, 

 "Morphological and Systematic Studies on the Cheilostomatous Bryozoa" 

 (1909), records 6 species from the West Indian and Florida region, describing 

 two of them as new. Otherwise this vast region remains untouched. As 

 the collections of Pourtales were made in the deeper waters of the Florida 

 region, it was presumed that careful collecting in the shallow waters would 

 disclose the presence of a somewhat different fauna, a presumption well 

 borne out by the results of my collecting. There is, indeed, a remarkable 

 disparity between the list given by Smitt and that forming the basis of the 

 present paper. Not only did 41 of the species described by Smitt fail to 

 appear in the shallow waters, but 40 others, whose presence was not hitherto 

 suspected in the Florida region, and many of them not even in America, 

 were taken. This brings the list of the species at present known from 

 Florida and West Indian waters up to 127. 



By comparing with lists from other regions where the bryozoa have been 

 carefully worked, it will be seen that the bryozoa fauna of the Tortugas 

 and of the Florida- West Indian regions is fairly rich in species and fairly 

 representative of tropical and semi-tropical regions. Careful collecting for 



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