Remarks on the Silurian OstraCode Genus Craspedobolbina from the Baltic Area and Britain

The original specimens of Craspedobolbina dietrichi Kummerow 1924, type species of the type genus of the family Craspedobolbinidae, were figured by Dr. H. Heidrich before they were lost in 1945, and these figures confirm the identity of the subsequently selected lectotype. The age of the species is claimed to be early Wenlockian.

The palaeocope faunas of the Graptolithengestein are characterized by two Craspedobolbina species, C. (Mitrobeyrichia) variolata and C. (Mitrobeyrichia) jonesi, type species of Mitrobeyrichia. The former species occurs in the oldest, late Wenlockian, parts of the Graptolithengestein. The latter species occurs in the Ludlovian zone of Lobograptus scanicus. Adult specimens of C. jonesi are figured and discribed for the first time.

The early Wenlockian species described from Shropshire as Bollia interrupta Jones 1887 is shown to be a Craspedobolbina with very characteristic cruminal morphology.