| Abstract/Notes | In a recent number of the “Neues Jahrbuch” (1901, Bd. ii, Heft 3, pp. 158–170, 6 text illust.) Dr. J. F. Pompeckj, of Munich, has an interesting paper on the genus Tmaegoceras. The genus was established by Hyatt1 in 1889 for the two very rare Ammonites from the Lower Lias of the Alps, Ammonites latesulcatus, F. v. Hauer, and Arietites levis, G. Geyer. To these, in 1899, G. Bonarelli4 added a third species, Tmaegoceras Paronai, from the Lower Lias of the Central Apennines, at the same time assigning to this genus Schafhäult's Ammonites Helli. But as Mojsisovics pointed out in 1893, Schafhäutl's species is a Tropites, whilst Ammonites latesculcatus, F. v. Hauer, Arietites levis, G. Geyer, and Tmaegoceras Paronai, G. Bonarelli, have nothing whatever to do with that genus. Of these three species Dr. Pompeckj regards Ammonites latesulcatus, F. v. Hauer, and Tmaegoceras Paronai, G. Bonarelli, as generically identical, and with them he unites also Quenstedt's Ammonites dorsosulcatus and his own new species (T. crassiceps), which he describes from the Lower Lias (zone of Arietites Bucklandi) in the neighbourhood of Tübingen (Württemberg). He considers Arietites levis, G. Geyer, to be a true Arietite, probably related to Arietites ophioides (d'Orb.), Wähner, or Arietites Cordieri, Canavari. |
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