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PART II: INTRODUCTION. (oul 
*Nomenclator Zoologicus,’ published in 1842-46, but since then 
apparently no attempt has been made to index the family and sub- 
family names of mammals. 
STABILITY. 
A family name differs radically from that of a species, genus or 
order, in being based on the name of one of its subordinate groups, its 
validity depending on whether its type genus is recognized or not. It 
carries its type, so to speak, within itself, and therefore can not be a 
nomen nudum in the sense in which a generic name may be, except 
when the genus on which it is based is a nomen nudum. Moreover, 
family names are rarely preoccupied, since there can not be two valid 
generic names having the same form in use at the same time. Occa- 
sionally it happens that a subfamily name of mammals may be pre- 
occupied by a similar name in another group, for example, E/obzéna 
Gill, 1872, a subfamily of murine rodents, is preoccupied by E/obzinz 
Adams, 1858, a subfamily of mollusks; the former is based on Z//o- 
bius, the latter on E//obzum, but the form of the subfamily name is 
identical in both cases. There is also the case of Grid: Thomas, 
1896, a family of dormice, preoccupied by Gliride Ogilby, 1837. 
However, in the latter case the earlier name is a descriptive term, and 
was not based on a generic name belonging to the same group. 
RELATIVE RANK. x 
The relative values assigned to families and subfamilies by dif- 
ferent authors have been almost as varied as the terminations 
employed. In some cases, names ending in ‘ina’ have been employed 
for groups higher than modern families—almost subordinal in rank. 
In other cases, they have been employed for tribes or groups 
subordinate to the subfamily. Owing to the resulting difficulty in 
indicating the relative rank the expedient has here been adopted 
of including all names between the genus and the order that end in 
“idi,’ ‘ide,’ ‘ida,’ as well as those that end in ‘ini,’ ‘ine,’ and ‘ina.’ 
The former are treated as families and the latter as subfamilies, irre- 
spective of whether the 77 names are termed subfamilies or the 77» 
names tribes or families. As in the Index of Genera no distinction is 
made between genera and subgenera, so here families and subfamilies 
are treated alike, except when a group has been proposed as a sub- 
family (with ending ‘ini,’ ‘ine,’ or * ina?) and later on raised to family 

third declension take idx and iadx. Blanchard has also called attention to the fact 
that family names in idx and iadx are masculine, while those of subfamilies in inc 
are feminine (Deux. Rapport Nomenclature Étres Organisés, présenté au Congrés 
Int. Zool. Moscou, pp. 30, 57, 1893). To overcome these difficulties, he proposed at 
the meeting of the International Zoological Congress, held in Moscow in 1892, six 
modifications to the rule for the formation of family names, but these modifications 
were not adopted. 
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