8 INDEX GENERUM MAMMALIUM. 
more restricted than that of a century or more ago, and consequently 
the recognized genera and subgenera have greatly increased in num- 
ber. Early authors gave little attention to questions of priority, and 
the difficulty of consulting current literature and of keeping abreast of 
investigations made in foreign lands was greater than at the present 
day; hence each author quoted only papers accessible to him and fre- 
quently overlooked those of his contemporaries. Thus, in several 
cases the same group received a different name in English, French, 
and German works. Generic names in all branches of zoology have 
now become so numerous that it is erowing more and more difficult to 
select those which have not previously been used in other classes; 
preoccupied names have consequently steadily increased in number, 
resulting in duplication, which, though difficult to avoid, is none the 
less to be avoided. Unnecessary duplication has also been introduced 
by the work of purists who refused to recognize barbaric or native 
names. The common names adopted as generic terms by Lacépéde, 
Lesson, and others, were rejected by Cuvier, Illiger, and their follow- 
ers, because such terms lacked classical origin or form. (See pp. 
29, 45.) 
]t is easy to see that under these conditions confusion increased as 
time went on, and it became more and more difficult to ascertain the 
proper name for any particular group. This difficulty has been less- 
ened somewhat in recent years by the publication of indexes of genera, 
of which 8 that include genera and subgenera of mammals may be 
mentioned in this connection. These are Agassiz’s ‘ Nomenclator 
Zoologicus,’ 1842-46; Bronn’s ‘ Index Paleontologicus,’ 1848; Mar- 
schall’s * Nomenclator Zoologicus, 1873; Seudder’s * Nomenclator 
Zoologicus, " 1882; Trouessart’s * Catalogus Mammalium,’ 1897-98; 
Sherborn’s ‘Index Animalium, 1902; C. O. Waterhouse's ‘ Index 
Zoologicus,’ 1902, and the annual volumes of the * Zoological Record.’ 
Agassiz’s * Nomenclator Zoologicus? brought together about 1,000 
names—most of those proposed prior to 1846; Marschall added 453 in 
1873; and all of these names were republished in Scudder's * Universal 
Index.’ Trouessart’s * Catalogue’ of 1898 is a list of recognized genera 
and species, and although including many synonyms, makes no pre- 
tense at completeness in this respect. The annual volumes of the 
‘Zoological Record’ contain lists of the new genera published during 
the year, but the early volumes did not contain the names of extinct 
groups, and thus far no general index of new names has been pub- 
lished. Agassiz and Marschall, moreover, give only references to the 
place of publication and volume in which published, without the page, 
which is often difficult to find. Scudder, in his ‘Supplemental List,’ 

“Seudder’s Nomenclator! consists of two parts: (1) ‘Supplemental List,’ con- 
taining chiefly additions to the indexes of Agassiz and Marschall, and (2) * Universal 
Index’ of the names published in the indexes of Agassiz, Marschall, Scudder, and 
the Zoological Record. Both parts were brought down to the close of 1879. 
