THE GENEALOGY or*rrsHEs
203
»(î890) and 'others,that the:Eïasmobranchs Were the*ÏOrei
runners of aÎI other groups. f—‘ _ If. the rearliest' true sh
could be found, it Would;ahnOst
Within—thé
sub—dass Elas“mc‘>bràneh "’ "
51895)-,'7°
_
This vieW isnot held so rmly —n0W5as
W
_
and from time to time
been1‘arsed ?
_against it ; especially,;that the
theiî‘îmodeof
*
and parts of
œ
uadoübtèdly “simpler. Eniphasis was
er'n_ ”
x
Ï_
What seemed to bethe*—mor'eprinüVe
ï_' _
and the
Cônditioh‘ ; : ».
that most
'a’
…
passmgphaseAcœrdmg -to,ithe ;geolog‘iéaî rebord {alsog
“
the*ä;Teïéôëtïä==èseémed; ”co-have been“
Iàter. in their
appearance, and hence it
thought that they had
degeneràted from-seine EIasmobranÇ‘h type.
L_ …
_-Ï;; There are two ways of searching for
'
_
ad"ch&tgétérs, through the g;ä010giçäl re‘eOrd andthrough Ï[
the
Both hâÿé,their drawbaeksand,
j:
iftake’separàtelÿ,may lead
!
: -
t :
.
:?îî
—
»
duectmn,theresults should be
sô fàr
-
_
_Ï
Presentknowledgegæs
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f f
-
CladœelachesowelldescnbedbyBashfŒdDean(ïg96)
”. is à pivotalformmîhlsconnection Itlssofaï‘feme‘œ‘ï
f’rîom mdnh1thttlkthntàtmghng
î
‘
of the -Elàsm0branÈhs1thadnodaspersand1ts
.
mOde d£ reproduction must
'
Èhemajôty ofthe 'Te‘l€osts
Openedseparatelyto the? exteïior,‘
tohaVeselvedasa—noperculum
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‘
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