UTRECHT MICROPALEONTOLOGICAL BUllETINS

whereas slightly asymmetrical variants of the latter form the scandodiform
elements (PI. 3, figs. 4a, b).
Acodiform elements were not found in the studied material.
The oistodiform element (see PI. 3, figs. la, b) has been described as
Scandodus furnishi LINDSTROM and this is the type-species of the form
genus Scandodus LINDSTROM. However, the shape of the base and its
orientation with regard to the cusp are rather typical for the oistodiform
elements of other species of the genus Drepanoistodus (see for instance the
more erect types of the oistodiform elements of Drepanoistodus inaequalis
(PANDER), emend. herein, see PI. 2, fig. 7. The lack of acodiform elements
and the rareness of oistodiform elements make the generic position of this
multi-element species doubtful.
Regional occurrence: At Kopingsklint this species occurs from the top of
member Kk 2 up to a level at about 2.20 m. above the base of the Bruddesta
Formation. In section 6 it was found from member Ka-d1 up to a level at
about 2.10 m. above the base of the Bruddesta Formation. Near Horns Udde
from the base of the member Ku up to a level at about 3.80 m. above the
base of the Bruddesta Formation. .
Biostratigraphic range: Drepanoistodus conulatus was found from the
Triangulodus subtilis/Gothodus microdentatus Assemblage Zone up to and
including part of the Microzarkodina flabellum Assemblage Zone (see
fig. 15).
Drepanoistodus forceps (LINDSTROM), emend. LINDSTROM, 1971
(PI. 2, figs. 14-22)
Oistodusforceps LINDSTROM, 1955a, p. 574, PI. 4, figs. 9-13; Fig. 3M.
Drepanoistodusforceps (LINDSTROM). LINDSTROM, 1971, p. 42, figs. 5,8.
Oistodus basiovalis SERGEEVA, 1963, p. 96, Pi. VII, figs. 6, 7.
Drepanoistodus basiovalis (SERGEEVA). LINDSTROM, 1?71, p. 43, figs. 6, 8.
Drepanodus suberectus (BRANSON & MEHL). LINDSTROM, 1955a, p. 568, Pi. 2, figs. 21,22.
Drepanodus planus LINDSTROM, 1955a, p. 565, Pi. 2, figs. 35-37; Fig. 4a.
Drepanodus homocurvatus LINDSTROM, 1955a, p. 563, PI. 2, figs. 23,24,39; Fig. 4d.
Acodus gratus LINDSTROM, 1955a, p. 545, PI. 2, figs. 27-29.
Remarks: Oistodiform and drepanodiform elements are most common in the
assemblage.
Amongst the scandodiform elements there are asymmetrical variants of
Drepanodus planus (see PI. 2, fig. 20) and forms which carry a lateral carina
and obviously occupy a position intermediate between Drepanodus homocurvatus
and Acodus gratus (see PI. 2, fig. 21). These scandodiform elements
were never described as separate form species.