AUTHOR'S PREFACE. 



THE selection of the Jurassic Bryozoa for the first Catalogue 

 may seem capricious ; but it was made deliberately. The 

 two orders of Bryozoa that prevailed in the Palaeozoic era 

 became extinct or greatly reduced in importance at its 

 close. It is among the Jurassic deposits that we have 

 to seek the ancestors of existing types of Bryozoa. They 

 occur there, moreover, with the primary lines of divergence 

 well marked, and not obscured by the extreme secondary 

 variations of later periods. It seemed, therefore, necessary 

 to work out the Jurassic fauna before attempting the 

 description of that of the Cretaceous, which of all British 

 Bryozoa faunas is most in need of further investigation. 



I must express my indebtedness to the Rev. T. Hincks, 

 F.R.S., for useful advice ; to Mr. Beeby Thompson, F.G.S., 

 and to Mr. E. Walford, F.G.S., for the gift to the 

 Museum, or loan, of specimens. Mr. C. D. Sherborn, 

 F.Z.S., has kindly permitted me to refer to his MS. Index 

 Generum 6t Specierum Animalium ; and my colleagues, 

 Messrs. R. B. Newton, G. C. Crick, and F. A. Bather, 

 have helped in the identification of fossils encrusted by 

 Bryozoa. For ever ready assistance in examining the recent 

 collections of Bryozoa, and the opportunity for frequent 



