HYDROIDS OF THE 1939 ALLAN HANCOCK CARIBBEAN 



SEA EXPEDITION 



By C. McLean Eraser 



When, in April, 1939, the Velero III passed through the Panama 

 Canal to make an exploratory trip through the Caribbean Sea as far east 

 as Trinidad and Tobago, the sea and the air were not very co-operative 

 and, in consequence, collecting marine biological specimens was often a 

 difficult, sometimes an impossible, procedure. Nevertheless, since the 

 region has been investigated so seldom, the results were well worth while. 



This is not the first time that hydroids have been reported from the 

 region traversed by the Velero III. Leloup has reported the greatest 

 number of species, one of them from the Island of Tortuguilla, Venezu- 

 ela, and all the rest of them from the Dutch West Indies : Bonaire, Little 

 Bonaire, Curagao, and Aruba. Versluys reported several from the vicinity 

 of Testigos Island, and one from Bahia Honda, Colombia. Nutting 

 reported one species from west of Colon, one from the Gulf of Darien, 

 and one from Trinidad. Eraser reported several from Maguaripe Bay, 

 Trinidad, collected by Elisabeth Deichmann. 



The number of species collected by the Hancock Expedition looks 

 small as compared with the total number previously reported, and yet 

 out of the thirty-seven species obtained and identified, only thirteen have 

 been reported previously from this region. Of the remaining twenty-four 

 species, six are described as new, hence the collecting is not lacking in 

 interest. 



This provides an opportunity to express my thanks to Captain 

 Hancock and his associates who provided the hydroid material, and to the 

 Allan Hancock Foundation for sorting out and sending the material for 

 examination. 



DISTRIBUTION 



Of the 37 species of hydroids obtained, only 10, Eudendrium tenel- 

 lum, Clytia noliformis, Gonothyraea gracilis, Endotheciutn paucinodum, 

 Sertularia exigua, Sertularia stookeyi, Sertidaria tiirbinnta, Thuiaria 

 crisioides, Callicarpa chazaliei, and Plumidaria diaphana, appeared at 

 more than one station. The species were distributed as follows : 



[1] 



