PREFACE. 



With this Preface the history of the British Fossil Cretaceous Bchinoidea is 

 brought to a close, and it only remains for the Author to record his warmest 

 acknowledgments to the many kind friends, enumerated in the retrospect, who 

 have generously assisted him in his long and laborious task. The duty imposed 

 upon him by the Council of the PaliEontographical Society, occasioned by the 

 untimely death of his distinguished colleague, Prof. Bdw. Forbes, F.R.S,, has 

 been much lightened by their ready, willing, and friendly aid at all times. 



When the Plates for this Monograph had been nearly completed his accom- 

 plished artist, Mr. Charles Bone, who had assisted him during so many years, like- 

 wise passed away ; so that in writing this preface the Author is solemnly reminded 

 of the mutability of all human undertakings, and desires to express his deep regret 

 that one who had aided him for nearly thirty years by steady, continiious, and 

 most accurate work, had not been spared to see the conclusion of his labours. 

 The Author, therefore, embraces the present opportunity of recording his high 

 appreciation of Mr. Bone's artistic drawings, which for beauty and accuracy in 

 lithographic art have not been surpassed, whilst all essential details relating to the 

 anatomical structure of the Echinoidea have been faithfully rendered throughout. 



The Author in an especial manner desires to return his warmest acknowledg- 

 ment and very best thanks to his old friend the Rev. Professor Wiltshire, F.G.S., 

 the indefatigable Secretary of the Palteontographical Society, for his unwearied 

 attention to every part of his work as it passed in successive years through the 

 press. The admirable summary of the British Cretaceous Echinoidea and 

 copious index which he has kindly contributed to complete this volume, have added 

 much to its value and general usefulness ; and he must further add that the liberal 



