UTRECHT MICROPALEONTOLOGICAL BUllETINS

sharppointed denticles, the edges of which may be partly confluent near
base" (op. cit. Stauffer, 1935, pp. 606-607).
Pravognathus aengensis LINDSTROM, 1955
(Pl. 2, fig. 23)
Regional occurrence: At Kopingsklint this species was found in member
Da- d 2 and Dk 1 . In section 6 and near Horns Udde it was not encountered.
Biostratigraphic range: Pravognathus aengensis was found in the Cordylodus
rotundatus and in the Drepanoistodus acuminatus Assemblage Zone (fig.
15).
Genus Prioniodus PANDER, emend. VAN WAMEL, herein
Type species: Prioniodus ele~ans PANDER, 1856.
Synonyms: Prioniodus PANDER, 1856, p. 29
Prioniodus PANDER, emend. LINDSTROM, 1971, p. 51
Baltoniodus LINDSTROM, 1971, p. 55
Gothodus LINDSTROM, emend. LINDSTROM, 1971, P. 54.
Remarks: Lindstrom (1971) distinguished a "Prioniodus group" with the
genus Prioniodus and a "Baltoniodus group" with the genera Baltoniodus
and Gothodus. The main differences between these groups are the absence of
an inner lateral flare and the lack of branches departing from the posterior
process of the prioniodiform elements in the "Prioniodus group". In addition,
these elements have no deep and wide basal cavity. However, we prefer,
for generic defini!ion of multi-element associations, to use the element
composition rather thaI; differences in shape between corresponding elements.
From our investigations Prioniodus elegans PANDER appeared to be
part of a multi-element assemblage with an elemental composition similar to
that of the multi-element genera Gothodus LINDSTROM, emend.
LINDSTROM, 1971 and Baltoniodus LINDSTROM. As a consequence, the
latter two genera are considered synonymous with the multi-element genus
Prioniodus, for :vhich the following redefinition is suggested:
Prioniodus is a multi-element genus with prioniodiform elements (after
Prioniodus PANDER, 1856); prioniodinaform elements (after Prioniodina
ULRICH & BASSLER, 1926); gothodiform elements (after Gothodus
LINDSTROM, 1955); tetraprioniodiform elements (after Tetraprioniodus
LINDSTROM, 1955) which are considered equivalent with oepikodiform
elements (after Oepikodus LINDSTROM, 1955) and/or trapezognathiform