UTRECHT MICROPALEONTOLOGICAL BUllETINS

Kk2 near Horns Udde (see locality 2, fig. 5) can not be correlated with
Tjernvik's zonation as this rock-section was not described by that author.
From the Aleklinta suite mentioned above, only the Oistodus lanceolatus/
Prioniodus deltatus Zone is present in member KkJ of section 14 near Horns
Udde; but here it would correspond to Tjervik's next higher Zone of
Megalaspides dalecarlicus (fig. 18). The latter correlation seems to disagree
with the position of the Oistodus lanceolatus/Prioniodus deltatus Zone at
the top of Tjernvik's Zone of Plesiomegalaspis planilimbata in section 6
(fig. 17). However, the boundary between both trilobite-zones at Aleklinta
was drawn rather arbitrarily by Tjernvik (fig. 17), and it is quite possible that
this boundary may be placed at a slightly lower level. It might well coincide
with the boundary between the Protopanderodus rectus/Oepikodus evae
Zone and the Oistodus lanceolatus/Prioniodus deltatus Zone. This would
imply, that in the area between Aleklinta and Djupvik the Protopanderodus
rectus/Oepikodus evae Zone forms the top part of Tjernvik's Zone of
Plesiomegalaspis planilimbata. The Oistodus lanceolatus/Prioniodus deltatus
Zone would thus be part of Tjernvik's Zone of Megalaspides dalecarlicus in
this area, as is the case in section 14 near Horns Udde.
According to Tjernvik, the lower portion of his Zone of Plesiomegalaspis
planilimbata corresponds with the Zone of Tetragraptus phyllograptoides,
and its upper portion corresponds with the Zone of Didymograptus balticus
of the Swedish shale facies. According to the same author (1956, p. 182),
the Zone of Tetragraptus phyllograptoides would be correlative with the
Upper Subzone of Tetragraptus of the British zonation, and the Zone of
Didymograptus balticus would correspond to the British Subzone of
Didymograptus deflexus (fig. 19).
On the basis of the considerations mentioned above, and according to
fig. 17, the Oistodus lanceolatus/Prioniodus deltatus Zone, the Oistodus
lanceolatus Zone, the Prioniodus crassulus Zone, the Prioniodus navis/
P.crassulus Zone, the Prioniodus navis/Stolodus stoIa Zone and part of the
Drepanoistodus forceps Zone together seem to correspond to Tjernvik's
Zone of Megalaspides dalecarlicus plus his Zone of Plesiomegalaspis estonica
at Aleklinta.
In section 14 near Horns Udde, Tjernvik's Zone of Megalaspides dale carlicus
together with his Zone of Plesiomegalaspis estonica seem to cover the
rock-interval with the Oistodus lanceolatus/Prioniodus deltatus Zone, the
Prioniodus crassulus Zone, the Prioniodus navis/P.crassulus Zone and the
Prioniodus navis/Stolodus stoIa Zone (fig. 18), thus within the conodontzone
interval of Aleklinta. According to fig. 16, however, the Prioniodus
crassulus Zone from the base of the Bruddesta Formation at Kopingsklint