410 Mr. A. R. Wallace on the Arrangement of the 
when we look to the next series of families, having only 9 
primaries, we find that there still exists the greatest diversity 
of opinion as to their true position. Every modern ornitho¬ 
logist, without exception, has attempted to intercalate them 
among the families of the first series, in some cases even in¬ 
corporating them into one or other of those families, owing to 
superficial resemblances. In this series the first of the nine 
primaries is always fully developed, and often very long; and 
this well-marked character is found to group together a set 
of families which have in many cases acknowledged affinities 
for each other, but which offer the greatest difficulties when 
we attempt to locate them naturally among the families of 
the first series. They have also a well-marked geographical 
aspect, being as characteristic of the New World as the pre¬ 
ceding series is of the Old. Four out of the ten families are 
exclusively American; one is peculiar to the Sandwich Islands, 
and has strong affinities to an American family; three others 
are as well represented in America as in the Old World; 
while the only one totally absent from America (Dicseidse) is 
typically Australian—that region which has the most affinity 
to the Neotropical. I now give a list of these families, and 
will then briefly remark on their affinities :— 
Series B. Tanagroid Passeres. 
Wing with 9 primaries, the first of which is fully developed and usually 
very long. 
1. Motacillidse. 
2. Mniotiltidae. 
3. Coerebidse. 
4. Drepanidse. 
5. Dicseidse. 
6. Ampelidse. 
7. Hirundinidse. 
8. Tanagridse. 
9. Fringillidse. 
10. Icteridse. 
The Motacillidie do not come well in series A; and there has 
been no general agreement as to their location. The Mnio- 
tiltidse and Coerebidse are so closely allied that good ornitho¬ 
logists differ as to where some of the genera (e. g. Dacnis , 
Certhiota) are to be placed; yet they cannot be arranged with 
their supposed allies in the first series without widely sepa¬ 
rating them. The Drepanidse of the Sandwich Islands, very 
