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370 GEOGRAPHICAL ZOOLOGY. [part iv.
Family 130.—PALAPTERYGID^. (2 Genera, 4 Species.)
Pala'pteryx (2 sp.) ; Euryapteryx (2 sp.).
These had a well-developed hind toe, and rudimentary wings.
Family 131.—^PYORNITHID^. (1 Genus, 3 Species.)
A gigantic Struthious bird (^pyornis), belonging to a distinct
family, inhabited Madagascar.
It was first made known by its enormous eggs, eight times
the bulk of those of the ostrich, which were found in a sub-
fossil condition. Considerable portions of skeletons have
since been discovered, showing that these huge birds formed
an altogether peculiar family of the order.
General Remarks on the Distribution of the Struthiones.
With the exception of the Ostrich, which has spread northward
into the Palsearctic region, the Struthious birds, living and
extinct, are confined to the Southern hemisphere, each continent
having its peculiar forms. It is a remarkable fact that the two
most nearly allied genera, Struthio and Rhea, should be found in
Africa and South Temperate America respectively. Equally re-
markable is the development of these large forms of wingless
birds in Australia and the adjacent islands, and especially in
New Zealand, where we have evidence which renders it probable
that about 20 species recently coexisted. This points to the
conclusion that New Zealand must, not long since, have formed
a much more extensive land, and that the diminution of its area
by subsidence has been one of the causes—and perhaps the
main one— in bringing about the extinction of many of the
larger species of these wingless birds.
The wide distribution of the Struthiones may, as we have
already suggested (Vol. I., p. 287.), be best explained, by sup-
posing them to represent a very ancient type of bird, developed
at a time when the more specialized carnivorous mammalia had