iv BRITISH FOSSIL ECHINODERMATA. 



Major Cockburn, Mr. Caleb Evans, Mr. Robert Etlieridge, and Mr. Weist. Messrs. E. T. 

 Newton and Sharman, Assistant Naturalists of the Jerrayn Street Museum, most kindly at 

 all times aided me in making selections of specimens for figuring in the plates. 



On the Continent I have had much friendly aid from MM. Gustave Cotteau, of 

 Auxerre, Perceval de Loriol, of Geneva, Herr Struckmann, of Hanover, Professor De 

 Koninck, of Liege, and the late MM. Seemann and Triger, of Paris. 



In addition to the valuable aid of the above kind friends, to vi^hom individually and 

 collectively I tender my warmest thanks, I have made many tours of inspection to all 

 the best private collections in England containing Chalk Echinoderms, and have visited 

 and worked the quarries in the different Cretaceous formations, in order to identify the 

 distribution of the species with the beds from whence they were said to have been 

 collected. All these proceedings have occupied much time, and were undertaken at a 

 period when I was fully occupied in the laborious practice of my profession, so that I found 

 much difficulty in bringing out the parts consecutively in the annual volumes of the 

 Palseontographical Society. 



The many duties and incessant occupation connected with my present position as 

 Medical Officer of Health having deprived me of the leisure necessary to continue my 

 sketch of the History of Echinology, I ventured to ask my much esteemed friend, M. 

 Perceval de Loriol (author of the ' Echinologie Helvetique ')j to undertake this portion of 

 the work. Monsieur de Loriol, with his usual kindness, consented to do so, I have, 

 therefore, now the pleasure of introducing his masterly sketch (for the translation of 

 which I alone am responsible) of the progress made in Echinology during the last twenty 

 years. For this most valuable addition to my work I beg to return my highly accom- 

 plished friend my very warmest thanks. 



" On the History of Echinology since 1863, by Perceval de Loriol. 



The fourth part of the vast Monograph, undertaken by Dr. Wright, relating to the 

 description of the Jurassic Echinides, was published in 1861. Dr. Wright had enriched 

 that part with a Table, giving a list of the works concerning the Echiuides, that had 

 come to his knowledge up to that date. It will not be without interest and utility, 

 therefore, to terminate the Monograph on the Cretaceous Echinides, to which Dr. Wright 

 is now adding the last pages, with a rapid review of the progress which has been accom- 

 plished during the last twenty years in the domain of Echinology, and to take a glance at 

 the magnificent discoveries for which we are indebted to the late Expeditions, which 

 had for their object the investigations of the depths of the sea. 



