DISTRIBUTION “IN TIME AND SPACE 229
these are of great
Lepidotus, with a peculiar
distorted mouth, has been found in the earlier deposits of
_
the Mesozoic periodÎ(Trias and Lias) of Europe; four species
occur
on
the boundaries between the ]ura'ssic and- the
Chalk.
Further, four species have been found-in theDec'can ' '
of India (Lias), and one of the
foundin the Wealden deposits of East Africa (Henniä,i9nt)ÿ
Lastly, the same family has been found in ‘ the Chalk ;of
Brazil. Other genera have been found in North America,
the Chalk-deposits of the Lebanon, and in the Iurassic_of
NewSouthVVales;
=
-'
,
,
,
'—
,
,
The Cosmopolitan range of the Protospondyli su‘icientlÿ
indicates their pelagic character. We see ; also, that the
-
Lemurian bridge between India and Madagascar has
disaPpeared, at least partly, during the Jurassic period and
'
that South America has been separated from Africa in the
'
Chalk period, as far north at least as the Amazon.
'
'
These pelagic forms, then, were abundant during the
_
Mèsozoic ”period and their" range extendedfrôrh ;Aus{tftaliär
'
-
'
(New 'SouthÏWal‘e‘s)
to
’—
'
and India,
Syria tô’lVddle Europe LandNorth
»
1Ç'They
with;the Clupeids
,_
.'
”ofthepresentÿ—daÿ through “a number of forms; especially
.
'
'
—
’
'
_
from' Australia to Europe,“ but—“hot :apparently1nNorth _?
America.
'The changes in strùCtùre conSÏst inithe; gradual_
replacement of the Gànoid by the cyCl0id scalesand the
acquirement of the interopetculum. The true Clupeids
occur abundantly in the Cretace0ns period in all parts of
'
the world, including South America and West AfriCa
.
(Guinea and Cameroon).
'
'
.
.
,
‘
“Going back a little, we have to note how this
;_form has from time to time thrown
various osh00ts,
'
which branched -oÎ
Twoofthese
"
may be
mentioned..- Chondrosteuswasa form
with Palæoniscid'iç=charac—‘tersWinch occurred Î_;_1I1 England
'
’
dungthlMpd _
_
the
g
-Ï'