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234
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THE BIOLOGY OF FISHES
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north, as, we understand th0se terms nowadays. It
believed,
example, that a wide communication must have
existed in Eastern Europe from the White Sea and Spitz;
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bergen in the north to the Caspian and Black Sea in the
south.
There may have been another and separate c0m—
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munication farther west, from the Adriatic northwarcls
across where the Alps now stand to Britain and
These and various other supposed connections can only 'Î
be conjectures, however, which are helpful in explaining
the distribution in the north of the ancient Ganoids and
Dipnoi.
The former, and especially the Cœlacanthidæ,
were extremely abundant, for example, from the Devonian
right on to the Chalk period, in Spitzbergen, Russia,
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'57.—'—Distribution of the modern Diphoi in South America;
Africa—, and Queensland.
(From Bridge.)
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Germany, Britain, Greenland, and North America. The
,
Dipnoi did >th extend so far north as Spitzbergen, but
their
many deposits ranging
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fï0mïnd1a,Persm, across ;gGérmany— and Britain to North '
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(F1g57)18WOÏÏhÿOÏStudyŸ;—There ;are}jho‘Dipnoans in ,
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thenorthatthepr68entday =Thethreerema1nmg forms
Coeur only1nthesouthernhexmsphereand ini:wide‘ly
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