. Bulletins of American paleontology. Alaskan ammonites, Pt. II: Westermann 37. 11 Text-fig. 11. — Cross-section of Phylloccras (Zftoccras) cf. P. zctcs (d'Orb.), phragmocone fragment, loc. WA IS in the Psrudocidoccras zonule (McM J 1018) ; X 1- Alaska. Imlay's specimen also has similar irregularly tetraphyllic saddles (from plastotype). P. zetes has recently been reinvestigated by Geczy (1967, p. 9) who concluded that in Hungary Zetoceras cannot be separated from PJiylloceras. Zetoceras is, therefore, placed as a subgenus in Phylloceras. The compressed whorl section with weakly convex, conver
. Bulletins of American paleontology. Alaskan ammonites, Pt. II: Westermann 37. 11 Text-fig. 11. — Cross-section of Phylloccras (Zftoccras) cf. P. zctcs (d'Orb.), phragmocone fragment, loc. WA IS in the Psrudocidoccras zonule (McM J 1018) ; X 1- Alaska. Imlay's specimen also has similar irregularly tetraphyllic saddles (from plastotype). P. zetes has recently been reinvestigated by Geczy (1967, p. 9) who concluded that in Hungary Zetoceras cannot be separated from PJiylloceras. Zetoceras is, therefore, placed as a subgenus in Phylloceras. The compressed whorl section with weakly convex, converging flanks, narrowly rounded venter, umbilical margin and overhang- ing umbilical wall, as well as the rectiradiate lirae and the septal suture match Geczy's specimen from the Pliensbachian of Hinigary. From Prince Patric Island in the Canadian Arctic, Frebold (1961, p. 5, pis. 7, 8, 9, fig. 2) described the dubious new species P. (Zetoceras) thorsteinssoni which was leased on a single totally septate internal mold and an undescribed fragment, the only certain differ- ence from P. zetes admittedly being its younger age; possible distinc- tions of the "new species" include a shallow umlDilical slope and missing radial folds. The Arctic specimens came from the Arkello- ceras beds of the Wilkie Point Formation which probably corres- pond to the O. saiizei Zone, a date based on the occurrence of Arkelloceras in the O. sauzei Zone of the Alberta foothills (Westermann, 1964b) and Wide Bay (Imlay, 1964, p. B53, pi. 28, figs. 7-9; generic identity here verified) .. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Paleontological Research Institution (Ithaca, N. Y. ); Columbia University. Ithaca, N. Y. , Paleontological Research Institution [etc. ]
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