UTRECHT MICROPALEONTOLOGICAL BUllETINS

d) The denticulation. Sometimes the second denticle is much bigger then
the others. There is no regularity in relative size of the denticles.
The connection between the basal parts of the cusp and the first denticle,
or between the first and second denticles is frequently very thin. This often
causes the units to break at these places.
Cordylodus caseyi DRUCE & JONES seems to be a sidewards bent variant
of Cordylodus angulatus PANDER. This variant occurs together with straight
forms in sample 1 of chart III.
The author fully agrees with Lindstrom (1955a, p. 552) that Cordylodus
intermedius FURNISH "falls well within the range of variation on Cordylodus
angulatus". Druce &. Jones' statement, that the basal cavity would be
distinctive for differentiation between Cordylodus angulatus PANDER and
Cordylodus intermedius FURNISH seems not to be. confirmed by their textfigures
23f and g. The anterior margin of the basal cavity of the specimen
figured in their figure 23g is not "gently concave" and its apex is not "directed
toward the anterior margin of the cusp", although these criteria are used by
these authors (p. 68) as distinctive features of the basal cavity of Cordylodus
intermedius FURNISH. Moreoyer, the shape of the basal cavity of Cordylodus
angulatus figured by Pander (1856, PI. 3, fig. lOa) is about intermediate
between those of Cordylodus intermedius FURNISH figured by Druce &
Jones, 1971, in their text-figures 23f and g.
The description of Cordylodus proavus by Muller (1959) entirely fits
to the more symmetrical and small specimens of Cordylodus angulatus (see
PI. 1, fig. 5 of this paper).
Regional occurrence: At Kopingsklint this species occurs from the base of
member Da-d 2 up to the top of member Kk 2. Between Aleklinta and
Djupvik, from the conglomerate halfway member Da-d3 up to the top of
member Ka-d 1. Near Horns Udde, from member Dh 1 up to and including
part of member Kk 2.
Biostratigraphic range: Cordylodus angulatus PANDER was found from the
Cordylodus angulatus/Cordylodus prion Assemblage Zone up to and including
the Stolodus stola Assemblage Zone (fig. 15).
Cordylodus prion LINDSTROM, 1955.
(PI. 1, figs. 8 and 9)
Cordylodus prion LINDSTROM, 1955a, p. 552, PI. 5, figs. 14-16.
Cordylodus oklahomensis MULLER, 1959, p. 447, PI. 15, figs. 15, 16; Fig. 3A. DRUCE & JONES,
1971, p. 69, PI. 5, figs. 6a-7c; Text-fig. 23j. JONES, 1971, p. 47, PI. 2, figs. 5a-8b.
Cordylodus lindstromi DRUCE & JONES, 1971, p. 68, PI. 1, figs. 7a-9b; Pi. 2, figs. 8a-c; Text-fig.
23h. JONES, 1971, p. 47, PI. 2, figs. 4a-c.