56 TYPE AMMONITES— III Dec. 



Editorial 



Volume III is now completed in 12 parts, containing ip? plates, 

 illustrating 137 species : there are also 3 portraits. Some 50 pages of 

 letterpress deal with chronology, classification and descriptions of many 

 more species : those which have been described, but not illustrated, in 

 the present volume will, it is hoped, find places in the next ; but the mass 

 of type-material which has accumulated is very great — much of it is 

 due to the activities of those geologists who take a keen interest in the 

 progress of this work. Where there is so much interesting material, 

 choice as to which should come for illustration is not easy : those speci- 

 mens which require little labour in the removal of matrix stand the best 

 chance, but specimens of new genera also have strong claims. It is 

 for this reason that the number of genera in the present volume is large — 

 the aim has been to illustrate genera, so as to lay a nomenclatorial 

 foundation, leaving till a later date the building up of the superstructure 

 with the various species of these genera. Already, what has been 

 accomplished in this way in the three volumes is having an appreciable 

 effect on nomenclature : it is not so often necessary to give the unsatis- 

 factory designation, Gen. nov. aff. But much remains to be done, 

 for the persistent richness of British Jurassic deposits in regard to 

 Ammonites is a most remarkable phenomenon : in some cases there are 

 preserved in Great Britain certain strata, with rich ammonite faunas, 

 which do not seem to be found anywhere on the Continent of Europe — 

 presumably, these strata have been wholly destroyed there. 



To all scientific friends who have kindly aided and encouraged this 

 study of Ammonites, and particularly to Mr. Tutcher, with his valued 

 photographic assistance, the Editor again tenders his hearty thanks. 

 To the subscribers who have so ably supported this work he is equally 

 grateful : he trusts that they will accord the same favour to the fourth 

 volume. To the Council of the Royal Society he would also express 

 kind thanks for material assistance in the shape of grants, which allowed 

 an increase in the number of plates. The author's friend and neighbour, 

 Mr. Walter Blaber, helped towards the same end, giving freely the 

 results of his long experience in the technicalities of book-production 

 and publication : with many thanks the author acknowledges his 

 indebtedness. As the sale of the work in various European countries 

 is greatly hampered by the problem of exchange, all such help is of the 

 greatest value. 



