VI PREFACE. 



tion to this effect was received by Professor Baird, and the opportunity 

 afforded me by Mr. Agassiz (to be mentioned below), determined me to 

 undertake the task. 



The usefulness of such a work need not be explained to the profes- 

 sional naturalist. To every one the nomeuclator and index of Agassiz, 

 so admirable in its execution, is a vade-mecum. The notorious inac- 

 curacy and incompleteness of Marschall's supplement to it on the other 

 hand, and the fact known to me both by personal study and by com- 

 munications of others, that several important works had altogether 

 escaped notice in any lists, determined me to make the new universal 

 index more complete and satisfactory by prefixing to it, in a single 

 alphabet, a supplemental list of names which had been omitted from or 

 incorrectly given in any of the previously published lists, so that they 

 could afterward be included in the general index. 



Confident, moreover, of the support I should receive from naturalists, 

 and appreciating the added value which authoritative statements from 

 first sources would have, a short notice of my project was published in 

 Nature,* and a circular was also prepared and widely distributed, in- 

 viting naturalists to send me lists of the genera founded by them in 

 recent years, to be included, over their names, in the proposed supple- 

 mental list. 



The responses to this appeal were so general, that I soon found the 

 task tenfold greater than I had anticipated, and although the work was 

 thereby rendered far more satisfactory, it involved so much more labor 

 that it would never have been attempted, if foreseen. This, however,, 

 has not deterred me from prosecuting it with the same care that would 

 have been given to a less arduous undertaking, although it has been at 

 a great sacrifice of time and strength. Not a few persons sent me com- 

 plete lists of their genera, including very many already reported, but 

 which I was unwilling to omit, from the value which attached to them 

 as furnished by the authors themselves. Early in my work I learned, 

 that a somewhat similar undertaking had been planned by some of the 

 staff of the British Museum, and I would gladly have left it to them, 

 had not steps been taken which pledged both the Smithsonian Institu- 

 tion and myself to the task ; and with great generosity the material 

 which had been collected by Mr. Waterhouse was placed in my hands. 

 How largely my list has profited by this courtesy, its own pages will 

 show. 



It is a special pleasure to acknowledge my indebtedness to Mr. Alex- 

 ander Agassiz, who freely placed at my disposal the manuscript addi- 

 tions and corrections which Professor Agassiz had made to his Nonien- 

 clator. These furnished the most considerable additions to my list, and 

 are particularly full in radiates, mollusks, and fishes.t They had been 

 collected under the direction of Professor Agassiz, during a long period of 



* Vol. 20, p. 551, October 9, 1879. 



t By an oversight, the principal additions to the lepidoptera, coleoptera aud ueu- 

 roptera were not received. 



