'
206;
THE '1BIOLQGY' OF FISHES
:
pect0ral n Was developed is unCertain, yet the base forsuch_f J
,
a _struCturÎe is ”present and not unlikethat found in the simpler
Teleosts like Clupea; C0nnected With the base we nd
-
the long pubic bar along the ventral margin which is present
'
,
in many Teleosts and represented perhaps by the pterygo'
'
podia of Cladoselache. As eXplained in Chap. V (p. 92) this
_
:
bar arises from the muscle buds along the abdominal wall and
Ÿ
is the base from which the pectora—l and ventral ns ai‘fise.
,
Here in the Arthrodirans the connection With the ventrals is
:
nearly—but not quite maintained. The coracoid portion of
'
î
'
thebar extends upwards- on the side and one of the plates
'
abovewàs hinged apparently on to the side of the skull, jùst . '
’
"as the clavicle—Or suprascapular may be similarly attached
'
*
the Teleosts of the present day.
'
,
—
=
-
=
g
greatest similarity of these Æthrodirans to' the
in the_ossication. It ”is admitted,
'
,"ÏÎ
.
'
of “the Èlas”mohranch theory,;
'
i
.
might fairly‘ be called paired parietals .
and'frontals, Whilst in Some cases bones comparable to the
,
!
elements of the third form of month (Chap. V), that 13,
'
maxillaries and premaxillarieS, have'_been detected.
’
Ï, ':
îhéSArthrôdijrans We—rémàrine forms,'Wheiethcj
'
" -::Ï
,
»_
'apparently’ freSh'Water' “shes.
'
_
_
Ïrelati0nshipbetween}them
_
ÿa—ndthe modem-marine Tdeoistsàs that
:.
,
.
;Çlàdgæ1æhç
!
:“
shewanothervarlantoftheD1pnoxTeleesttypeThe
Lana—ana, -:
'
E'
diScover€d which,
'
"
:1t18
earliest knownshes.
.'{'
:"»
of a peculiar kind;
;
a SÏQgÏÔ_
and—à
ThereWefe no'paired-nsÊ ,'
if ï Whattheghcadïwas
doi, I_1;Ot know
__