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466 GEOGRAPHICAL ZOOLOGY. [part iv.
Trachinidae possesses a fresh-water genus, Aphritis, one species
of which inhabits Tasmania, and two others Patagonia ; the
Haplochitonidse (2 genera, 3 sp.) are found only in Tierra del
Fuego, the Falkland Islands, and South Australia; and the
Galax idse (1 genus, 12 sp.) inhabit the same regions, but extend
to Chili, to New Zealand and to Queensland. We have here an
illustration of that connection between South America and
Australia which is so strongly manifested in plants, but of which
there are only scattered indications in most classes of animals.
The dividing line across the Malay Archipelago, separating the
Oriental from the Australian regions, and which is so strikingly
marked in mammalia and birds, is equally so in fresh-water
fishes. No less than six families have their eastern limits in
Java and Borneo ; while the extensive family of Cyprinidse has
no less than 23 genera in Java and Borneo, but not a single
species has been found in Celebes or the Moluccas.
The distribution of fresh-water fishes lends no support to the
view that the peninsula of India belongs to the Ethiopian
region. A large proportion of the Oriental families are common
to the whole region ; while there is hardly a single example, of
a characteristic Ethiopian family or genus extending into the
peninsula of India and no further.
Among the special peculiarities of distribution, is the curious
fish, forming the family Comephoridae, which is confined to Lake
Baikal, among the mountains of Central Asia, 2,000 feet above
the sea, and a thousand miles distant from the ocean ; yet
having its nearest allies in the exclusively oceanic family of the
mackerels (Scomberidse). The Characinidse are confined to Africa
and South America, distinct genera inhabiting each region. The
Salmonidae are confined to the two northern regions, except a
single species of a peculiar genus in New Zealand. The genus
Osteoglossum has a species in South America, another in the
Sunda Islands, and a third in Queensland ; while the curious
Sirenoidei are represented by single species of peculiar genera
in Tropical America, Tropical Africa, and Tropical Australia.
Fossil Fishes.—Fishes have existed from a very remote era,
and it is remarkable that the first whose remains have been dis-