Article: On the graptolites described by Baily (1871) from the Silurian of Northern Ireland and the genus Streptograptus Yin

The graptolite faunas described by Baily in 1871 from County Down, N. Ireland are re-examined and assigned to the middle part of the Monograptus turriculatus Biozone of the Telychian (Upper Llandovery). One of Daily's new species, Graptolithus plumosus, is redescribed and a neotype selected. It is suggested that G. plumosus is the valid type species of the genus Streptograptus Yin, 1937, but was misidentified by Yin as M. nodifer Tornquist, 1881. An emended generic diagnosis for Streptograptus is given.