INTRODUCTORY NOTE. 



During the 10 years which have elapsed since the publication of Part II of this work, in 

 1904, a number of new workers have arisen in the field of marine zoology and not a few of these 

 have produced valuable works on the H5^droida and described many new species of Cam- 

 panularidse. It remains true, however, that no one has attempted to give a comprehensive 

 account of American forms, although the west coast of North America has been the recipient 

 of special attention by several able writers, such as Harry Beal Torrey and Charles McLean 

 Fraser. 



The east coast of North America has received but scant attention, and the South American 

 hydroid fauna has been exploited almost exclusively by European writers, particularly 

 Dr. Clemens Hartlaub and Dr. Elof Jaderholm. To both of these writers the author is indebted 

 for specimens and literature. 



Here, as in the case of Part II, comparatively few new species have been described, and 

 the rather imposing array of 82 species of Campanularidee is more the result of carefully con- 

 sulting the literature of the subject both in America and abroad, and in obtaining material 

 illustrating the forms therein described, than of the discovery of new species. 



In the extensive bibliographic work involved, the author gratefully acknowledges courte- 

 sies by many private correspondents, and by the Librarians of the Congressional Library; the 

 John Crerar Library in Chicago; the Field Columbian Museum, Chicago; the Harper Memorial 

 Library, Chicago; and the Chicago Public Library. 



In addition to the help rendered by the above-mentioned friends and institutions, I take 

 pleasure in acknowledging the assistance of the following: 



The directors of the British Museum (Natural History) for portions of some of the type 

 specimens of Campanularidse collected by the Challenger; the United States Bureau of Fish 

 and Fisheries, for permission to include descriptions of new Campanularidje found in their 

 collections; Prof. Maurice Bedot, of Geneva; Mr. W. M. Bale, of Kew, Victoria; Dr. Armand 

 Billard, Paris; Dr. Hjalmar Broch, Trondhjem, Norway; Mr. E. T. Browne, University Col- 

 lege, London; Prof. Sydney J. Hickson, Manchester, England; Mr. Paul E. Kramp, Copenhagen; 

 Mr. A. Kiihn, Freiburg; Prof. G. M. E. Levinsen, Copenhagen; Mr. James Ritchie, Edinburgh; 

 Mr. B. Saemundsson, Reykjavik, Iceland; Dr. E. Stechow, Munich. 



I take pleasure also in expressing my obligation to the following American colleagues, who 

 have generously aided me in the matter of literature or specimens, often both: Prof. Gary N. 

 Calkins, Dr. C. M. Fraser, Dr. Charles W. Hargitt, Dr. A. G. Mayer, Dr. Harry Beal Torrey, 

 and Prof. A. E. Verrill. 



