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CHAP. XVII.] MAMMALIA- 179
discovered, which are believed to belong to this sub-order : but
they form two distinct families,—Lemuravidse and Limnotheridse.
Other remains from the Miocene are believed to be intermediate
between these and the Cebidee,—a most interesting and suggestive
afiinity, if well founded. For the genera of these American
Lemuroidea, see vol, i., p. 133.
General Remarks on the Distribution of Primates.
The most striking fact presented by this order, from our present
point of view, is the strict limitation of well-marked families to
definite areas. The Cebidse and Hapalidae would alone serve
to mark out tropical America as the nucleus of one of the great
zoological divisions of the earth. In the Eastern Hemisphere,
the corresponding fact is the entire absence of the order from
the Australian region, with the exception of one or two outlying
forms, which have evidently transgressed the normal limits of
their group. The separation of the Ethiopian and Oriental
regions is, in this order, mainly indicated by the distribution of
the genera, no one of which is common to the two regions. The
two highest families, the Simiidse and the Semnopithecidse, are
pretty equally distributed about two equatorial foci, one situated
in West Africa, the other in the Malay archipelago,— in Borneo
or the Peninsula of Malacca ;—while the third family, Cynopithecidse,
ranges over the whole of both regions, and somewhat
overpasses their limits. The Lemuroid group, on the other
hand, o^ers us one of the most singular phenomena in geo-
graphical distribution. It consists of three families, the species
of which are grouped into six sub-families and 13 genera. One
of these families and two of the sub-families, comprising 7
genera, and no less than 30 out of the total of 50 species, are
confined to the one island of Madagascar. Of the remainder,
3 genera, comprising 15 species, are spread over tropical Africa
while three other genera with 5 species, inhabit certain restricted
portions of India and the Malay islands. These curious facts
point unmistakably to the former existence of a large tract of
land in what is now the Indian Oc^an, connecting Madagascar on
the one hand with Ceylon, and with the Malay countries on the
;