parvulus; and all
from James and Chatham Islands (between which two other islands are
situated, as connecting links) belonged to M. melanotis. These two
latter species are closely allied, and would by some ornithologists
be considered as only well-marked races or varieties; but the Mimus
trifasciatus is very distinct. Unfortunately most of the specimens
of the finch tribe were mingled together; but I have strong reasons
to suspect that some of the species of the sub-group Geospiza are
confined to separate islands. If the different islands have their
representatives of Geospiza, it may help to explain the singularly
large number of the species of this sub-group in this one small
archipelago, and as a probable consequence of their numbers, the
perfectly graduated series in the size of their beaks. Two species
of the sub-group Cactornis, and two of the Camarhynchus, were
procured in the archipelago; and of the numerous specimens of these
two sub-groups shot by four collectors at James Island, all were
found to belong to one species of each; whereas the numerous
specimens shot either on Chatham or Charles Island (for the two
sets were mingled together) all belonged to the two other species:
hence we may feel almost sure that these islands possess their
representative species of these two sub-groups.
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