PKEFACE. 



Ma,„ 



ly years ago I undertook a study of the Danish cretaceous Brijozoa the 

 results of which have not yet been pubiislied, and among the species studied by me 

 were also a small number belonging to the family Melicerititidae (Eleidae d'Orb.) 

 to the members of which d'Orbigny ascribes a calcareous operculum the presence 

 of which, however, has been denied by all the later authors who interprete the 

 supposed operculum as a closure-plate of the same nature as that which has 

 been found both in the Cijclostomata and the Cheilostoinata. I came however to the 

 result that d'Orbigny was right in his interpretation of the named structure, and I 

 have published some remarks on this subject in my preliminary communication 

 sStudies on Bryozoa« '). As later I wished to make a more comprehensive study 

 of this interesting group I extended my investigations over a number of foreign 

 species, and in this etTort I have been supported by several colleagues abroad. In 

 the first instance I owe a debt of gratitude to Dr. F. Canu the author of so many 

 valuable works on fossil Bryozoa, who has not only sent to me a large number of 

 French species defined by him, but also helped me to acquire materials containing 

 cretaceous bryozoa from a number of French localities. A similar material from a 

 few other French localities has been sent me by Mr. G. Dollfus, and to Mr. M. 

 FiLiozAT who has made a special study of the cretaceous Bryozoa from Vendome 

 I owe the possession of a number of species from that locality. For the gift or 

 loan of specimens I am also indebted to Mr. A. W. Waters, Dr. E. Pergens, Prof. Dr. 

 G. Steinmann, Bonn and Prof. Dr. H. Wegner, Miinster, and lastly I have been able 

 to acquire a collection of cretaceous Bryozoa from the Chatham chalk, by the aid 

 of Mr. W. Gamble. To all these gentlemen I offer my sincere thanks. 



Zoological Museum of Copenhagen. /"* A/T R T 



August 16, 1912. ^- "^- ^- •L'EVINSEN. 



16. 



