A Revision of Wiman's Dendroid and Tuboid Graptolites

The dendroid, and what are now recognised as tuboid, graptolites described by Carl Wiman in a series of papers in this Bulletin between the years 1895 and 1901 are mostly preserved as microtome seetians in the Palaeontological Institute at Uppsala. Many of them retain traces at !east of their detailed interna! structure and can be re-interpreted in the light of present-day knowledge. From amongst this collection the following species are here described: - Dendroidea: Dendrograptus maximus Wiman, D. oelandicus Wiman, D. balticus Wiman, Dendrograptus sp. (= Sp. no. I of Wiman); Dictyonema cavernosum Wiman, D. peltatum Wiman; Acanthograptus musciformis (Wiman), A. impar sp. nov.; Caremagraptus formasus (Wiman). Tuboidea: Reticulograptus tuberasus (Wiman), Galeograptus wennersteni Wiman and Discograptus schmidti Wiman. For these and all other Wiman species, lectotypes have been chosen, and descriptions of two non-Scandinavian species Reticulograptus thorsteinssoni sp. nov. and Galeograptus nicholasi sp. nov. are included for comparison. A new type of theca narned the conotheca, possibly a modified autotheca, is described in Reticulograptus and Discograptus and reconstructions from serial seetians of Galeograptus wennersteni have revealed a notable apertural modification of the basal autothecae