INTRODUCTION. 



The total number of species referred to the genus Madrepora s. s. up to 1890, 

 when the present work was undertaken, appears to be 157, not including the 

 nomina nuda of Valenciennes and other authors. To these must be added 

 twelve or fourteen others recently published by Rehberg. In most cases the 

 species recorded by the various authors have been identified from published 

 descriptions, and I am not aware that any author has compared together the 

 type specimens contained in continental museums. The American types have 

 not been redescribed or refigured since the original publication. The synonymy, 

 therefore, lapsed into a state of confusion, and the lists of species recorded as 

 occurring in certain areas are quite unreliable. It has thus been necessary to 

 make, as far as possible, a renewed study of the type specimens of the numerous 

 species already described. It has not yet been possible for me to study the type 

 specimens preserved at Washington and other places in the United States, and 

 thus I have only been able to judge of the characters and positions of the species 

 described by Dana, Horn, and Verrill from the more or less complete data 

 supplied by these authors. The types described by European authors are in the 

 Museums of Paris, Berlin, London, Strassburg, and Jena, whilst Klunzinger's 

 types are, I believe, preserved in the Museum at Stuttgart, but a complete set is 

 also to be found in the Berlin Collection. I have hot yet had an opportunity of 

 visiting the Stuttgart Museum, and my notes on Klunzinger's Red Sea Collection 

 are based on the study of the specimens identified by Klunzinger which aie 

 contained in the Berlin and London Collections. 



