BRYOZOA OF THE ALLAN HANCOCK 

 ATLANTIC EXPEDITION, 1939 



(Plates 1-6) 

 Raymond C. Osburn 



RESEARCH ASSOCIATE 

 ALLAN HANCOCK FOUNDATION 



During the month of April, 1939, with the Velero III, a collecting 

 expedition was made into the Caribbean Sea. The full details of the 

 expedition are given in the account by Dr, John S. Garth, "Geographical 

 Account and Station Records of Velero III in Atlantic Waters in 1939," 

 Allan Hancock Atlantic Expedition Report Number 1. 



The course of the cruise was from the Panama Canal eastward along 

 the coasts of Panama, Colombia, and Venezuela as far as the islands of 

 Trinidad and Tobago, and returning over much of the same course. The 

 dredging was all done on the coastal shelf, 71 fathoms being the deepest 

 haul. Much of the bottom in this area consists of sand and mud which 

 are usually unfavorable to the development of a rich attached benthic 

 fauna. Since ecological conditions apparently did not vary to any great 

 extent, the list of 107 bryozoan species is unexpectedly large. 



Very little such collecting has been done in this region and the records 

 are therefore of special interest for distributional studies. The only paper 

 dealing with the Bryozoa within this area is an account by the writer 

 (Osburn 1927) of 23 species taken at Curagao Island by Dr. C. J. van 

 der Horst (Bijdragen tot de Kennis der Fauna van Curagao. Resultaten 

 eener Reis van Dr. C. J. van der Horst in 1920). Dr. van der Horst 's 

 collections were all made in shallow water about the harbors of Curagao. 



The first important work on the Bryozoa of the general West Indian 

 area was that of Smitt, the Swedish naturalist, who studied and reported 

 on the collections made by Count L. F. de Pourtales in the region of 

 southern Florida (Smitt 1872 and 1873). In 1908 Osburn collected 

 Bryozoa about the Oceanic Laboratory of the Carnegie Institution at 

 the Tortugas Islands, Florida, (1914), and in 1927 reported on a col- 

 lection made by van der Horst at Curagao. In 1928 Canu and Bassler 

 published an important paper on the collections made, especially by the 

 Albatross, in the Gulf of Mexico, Florida Straits and vicinity. This was 

 followed by Osburn's report on his collections in the vicinity of Porto 



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