On the Graptolites described by Baily (1871) from the Silurian of Northern Ireland and the Streptograptus Yin

The graptolite faunas described by Baily in 1871 from County Down, N. Ireland are reexamined and assigned to the middle part of the Monograptus turriculatus Biozone of the Telychian (Upper Llandovery). One of Baily'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 Törnquist, 1881. An emended generic diagnosis for Streptograptus is given.