HYDROIDS OF THE 1936 AND 1937 ALLAN HANCOCK 



PACIFIC EXPEDITIONS 



C. McLean Fraser 



In each of the seven Hancock Expeditions to date, 1932-1938, hy- 

 droids have been collected. In 1934 special attention was paid to hydroid 

 collecting and the collection obtained has been reported upon by itself. 

 In 1936 and 1937 collections u^ere made in a somewhat restricted and 

 well-defined area, no part of which was visited in the 1934 Expedition. 

 It includes the west coast of Lower California, north of Cerros Island, 

 and the Gulf of California. 



It might have been well to include the remainder of the west coast 

 of Lower California in this general area, but much material was ob- 

 tained from this region in 1934, and this has already received attention. 

 No collections were made there in 1936 and 1937. 



The hydroids collected in the other four years, 1932, 1933, 1935, 

 and 1938, will be treated together later. 



Again I wish to acknowledge my obligation to Captain Hancock, 

 his officers and ship's company of the velero hi and all those associated 

 with these Expeditions for the collection and the preservation of the 

 hydroids. Dr. Irene McCulloch of the Department of Zoology of The 

 LTniversity of Southern California sorted the material and looked after 

 it until it was forwarded for examination. Her many kindnesses and 

 her continued interest in the progress of the work are much appreciated. 

 To Dr. Josephine F. L. Hart I am indebted for the drawings used in 

 illustration. 



Distribution 



Of the 56 species in the collection, nine are described as new (the 

 gonosome of Antennularia tetraseriata Fraser is described for the first 

 time). Of the 47 species previously reported, 36 appeared in the 1934 

 collection. Of the eleven species that did not so appear, ten have been 

 reported from farther north along the Pacific coast, and one, Plumu- 

 laria attenuata Allman, from the West Indian region. 



Ten species were obtained from the west coast of Lower California, 

 one of them, Abietinaria expansa, being new. Of these only one species, 

 Aglaophenia octocarpa Nutting, was obtained in the Gulf of California, 



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