INTRODUCTION. 



When studying any group of animals from a systematic point of view, the 

 first fact that forces itself on the notice of the student is that certain forms, 

 identical one with another, have been described under different and even many 

 names by different observers. This, in most cases, has been caused by the 

 describer being ignorant or regardless of the writings of those who have gone 

 before. In no group, perhaps, is this lamentable state of things presented 

 more forcibly than with the Foraminifera ; and it was in order to leave no 

 excuse for those who came after me, that I prepared a Bibliography of the 

 subject in 1888, and in 1890 compiled an index to the contents of all publica- 

 tions on this special group known to me as issued up to December, 1889, which 

 Index the Smithsonian Institution has done me the honor to publish. It is 

 now, therefore, quite an easy matter to arrive at the number and names of 

 species of any genus, and, with this help, to examine and compare those forms 

 previously figured and described with the form supposed to be new ; for even 

 in the absence of the literature, friends can always supply tracings of the 

 figures described. 



It is chiefly to the efforts of William Kitchen Parker, Thomas Rupert 

 Jones, and Henry Bowman Brady, that we owe the clearing up and ordering 

 of the nomenclature of the older authors. Professor Rupert Jones, the prime 

 mover in the work, is happily still with us. So long ago as 1859, the two 

 first-named of these microscopists commenced a series of papers " On the 

 Nomenclature of the Foraminifera " in the " Annals and Magazine of Natural 

 History," and these were continued, as a series, for about fifteen years. Al- 

 most all the old authors were reviewed in their turn, and the result was a 

 considerable simplification of specific nomenclature. Brady, whose acquaint- 

 ance with recent forms is attested by the " Challenger " Report, did still more 

 in this direction ; and of later years Axel Goes, of Kisa, Sweden, has tabulated 

 recent and fossil forms around well-marked varieties. This method, previ- 

 ously adopted by Parker and Jones, tends to support the idea of the impossi- 

 bility of defining a " species " in a group where every individual may be re- 

 garded as a " variety." 



In the compilation of this Index many references have been given to forms 

 described but not figured : the existence of such names necessarily leads to an 

 incomplete index ; it is an easy matter to overlook a name if not accompanied 

 by a figure. As it is, moreover, practically useless to describe a form as new, 

 without a figure, in a group so variable in itself, the great majority of these 



