100 Zoological Nomenclature. 
But when the a free is more ertensive than the earlier, the following 
rule guns 7 tion 
ne equbealinl te to several earlier ones is to be canceled. J—The same 
soacinie s which is involved in § 6 will apply to § 8 
§ 8. If the later name be so defined as to be equal in ex- 
tent to two or more previously published genera, it must be 
canceled in toto. 
Example.—Psarocolius Wag)., 1827, is equivalent to five or six genera 
athe 8 published under other names, therefore Psarocolius should be 
celed. 
shee previously published genera be separately adopted (as is the case 
=r the equivalents of Psarocolius), their original names will of course 
neces but if we follow the later author in combining them into one, the 
following 1 : ea is necessary :— 
A unded of two or more previously proposed genera whose cha 
acters sage now deemed insufficient, should retain the name of one coe them. Le It 
sometimes happens that the progress of science requires two o e gener 
founded on insufficient or erroneous characters, to be aakack ai ae 
one. - such cases the law of priority forbids us to cancel ail the original 
ound genus. We must there ri 
names im 
select bene one species as a type or example, and give the gers nam 
which it formerly bore to the whole group now formed. If thes > ioe 
- generic names differ in date, the oldest one should be the one adop- 
§ 9. In compounding a genus out of several smaller ones, 
the sarticst of them, if otherwise unobjectionable, should be 
selected, and its former generic name be extended over the new 
genus so compounded, 
' Example.—The genera, Aecentor and Prunella of Vieillot, not being consid- 
‘ered sufficiently distinct in character, are now united under the general 
i rliest. 
e now proceed to point out those few cases which form exceptions to rt 
law of priority, and in pres te it acini — justifiable and necessary t 
alter the names originally imposed by author 
ld be changed whe vate lied to another 
mt retains it.|—It being essential to the binomial method to indicate objects 
in natural history by means of two words only, without the aid o' fi T 
similar reason, no two species in the same genus should bear the same name.* 
When these cases occur, so tater of the two duplicate names should be can- 
celed, and a new term, or the earliest synonym, if there be any, substituted. 
~ rin —, of this rule oe oo agp obvious and —- _ its ap- 
lication is not always easy, a well established specifi me is 
— to ae identical ‘with an older sais rehash may be an old and ra nopleetid 
other i _ 
Sh 1 
when on this account a specific name has been changed before the generic sepa- 
= shoul essen rejected name be restored after the separation? We think 
