PREFACE. 
vii 
Both Scudder’s list and our Index include a considerable number of names that 
are merely synonyms. I should think that about one-third may be deducted on 
this account and for other reasons ; if, therefore, we take 40,000 from the 120,000 
names included in the two works, we have 80,000 as the number of names in use 
in Zoology (including Palaeontology) at the present time for genera and subgenera* 
The annual crop of new names is increasing in a striking manner. Of the 40,000 
names in our Index, about 6000 belong to the period antecedent to 1880. If 
we subtract this number from our list and add it to that of Scudder, we note 
that during the period from 1758 to 1879, 86,000 names were proposed, i.e. about 
775 annually ; while from 1880 to 1900 some 33,000 names, or about 1150 per 
annum, were set out. The discrepancy between the two periods is really very 
much greater than this, because Scudder’s list includes family and other names 
that are not indexed in the “ Zoological Record.” Hence it is safe to say that the 
proposal of new names has gone on with increasing profusion, and was in 1900 
about three times as great as it was a century ago. If we add to this considera- 
tion the conviction of many zoologists, that not above one-tenth of existing 
animals is known, and not one-hundredth part of the extinct forms, it is clear 
that the proposal of new names is likely to continue its rate of growth ; so that 
the necessity for Indexes and Records of a complete and comprehensive nature 
cannot be doubted. 
There is one point of a general nature that should be alluded to ; it is 
connected with emended names. In the preparation of such a list as this, grave 
difficulties arise from the practice of many zoologists of emending a name with- 
out stating that they are making a new name. The methods of the earlier 
writers were very loose in this respect, and it is consequently in many cases 
difficult to trace the history of names that are at present in use. Every writer 
who proposes to alter a name that has boen previously proposed should do so in 
a formal manner, and the altered name should then find its way into Indexes as 
it would do if it were an altogether new name.* It is impossible to draw a line 
between emended names and new names, and the right course is to treat emended 
names and new names as being of one category. 
* The writer of this preface is not to be treated as a supporter of the practice of 
altering and amending names. On the contrary, he is of opinion that every name of a 
genus should be used in the form in which it was originally proposed, nothing but 
errors that are obviously printer’s errors being corrected. The best course is to leave 
names alone. But all authors do not agree to this, and we must therefore insist that 
those who propose alterations should do so in a formal manner. 
