EDITOES PREFACE TO THE SECOND EDITION 



A NEW English edition of von Zittel's Text-hook of Fakontology having been 

 called for, advantage was taken of the opportunity to prepare a thorough- 

 going revision of the first volume, in order that an adequate account might 

 be incorporated of the new knowledge that has been gained during recent 

 years. 



Towards this end, a number of specialists were invited to collaborate Avith 

 the Editor in preparing a fresh treatment of the leading groups of Inverte- 

 brates, and the jDresent work bears witness to the generous response that was 

 made to this invitation. Many parts of the work have been entirely re- 

 written, others have been emended, rearranged and enlarged, and the 

 classification in various places has been very considerably altered. The new 

 work, therefore, cannot Avith either justice or propriety be called von 

 Zittel's Text-book, being in eifect a composite production ; and 3'^et in scope 

 and style it is modelled after the well-known G erman original. 



The names of the difterent collaborators appear on the title-page, and the 

 sections that have been revised or rewritten are credited in the body of the 

 work to the specialists responsible for them. To all of his collaborators 

 the Editor desires to otter grateful acknowledgments, and to express the 

 sense of his own personal indebtedness to them for the large service they have 

 rendered, and for many individual courtesies. 



To his friend and former associate at Harvard, Doctor Robert Tracy 

 Jackson, the Editor is under an obligation greater than can be adequately 

 acknowledged ; for besides having contributed practically a fresh account of 

 the Echini, Dr. Jackson has carefully read the proofs of the entire work, and 

 has offered in many places most valuable suggestions and emendations. Like 

 several of the other collaborators, also, he has fui'nished the originals for a 

 number of new figures. The total number of fresh illustrations has thus been 

 sensibly increased. It is hoped that the large amount of painstaking work 

 which has been bestowed upon the present treatise will be found to yield 

 returns in increased value and usefulness among students of Paleontology 

 generally. 



CHARLES R. EASTMAN. 



Carnegie Museum, Pittsburgh, 

 Pennsylvania, June 5, 1913. 



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