Graptolites from the Ontikan Limestones (Ordovician) of Öland, Sweden. II. Graptoloidea and Graptovermida

Descriptions are given of eighteen species and two subspecies of graptoloids and a possible graptovermid species from the Lower Ordavieian Ontikan Iimestones of northern Öland. One new graptoloid genus, Aulograptus gen. nov., is proposed and two other genera, Holmograptus Kozlowski and Maeandrograptus Moberg, are re-diagnosed. Two new species are described from Öland: one possibly belongs in Maeandrograptus, M. ? genieulatus sp. nov., and the other is attributed to Pseudoclimacograptus Pribyl, P. camptochilus sp. nov. The syntypes of Tetragraptus bigsbyi (Hall, I86s) are re-examined and shown to include two species. Glyptograptus austrodentatus var. oelandicus Bulman is eIevated to the status of subspecies thereby becoming available in terms of the rules governing zoological nomenclature. The taxonornie status of the family Corynoididae Ruedemann is discussed. lt is considered probable that Atopograptus Harris and Janograptus Tullberg are invalid genera, having been founded on regenerated fragments of normal dichograptid rhabdosomes. The leve! of the boundary between the graptolite Zones of D. hirundo and D. bifidus is concluded to lie between -I I 8D and + 23D at Hälludden and between - 83 and D at Hagudden. In terms of the substage divisions of the Balto-Seandian Ordavieian limestone sequence, the graptolite zonal boundary lies either at the Hunderum-Valaste junction or with in the upper part of the Hunderum Substage.