In this communication I purpose describing a few new forms of Graptolites which I have obtained at various times from the Llandeilo rocks of the south of Scotland. Of one species, first collected at Moffat in 1866, a brief diagnosis has previously been given, and the names of two others, from the lead-mining district of Lanarkshire, have already been published. One of these also occurs near Moffat. The remaining species are all from one or other of these richly fossiliferous districts. Of their position in the geological series I need only say here that the black, more or less carbonaceous, shale in which they occur, appears, from the fossils it contains, to correspond to the higher portion of the Llandeilo flags of Wales; that it is almost immediately succeeded by a series of beds (the Gala group) containing fossils of Caradoc or Bala age; and that the unfossiliferous flagstone, or greywacké, in which it occurs, reposes on rocks which have yielded to the persevering search of Prof. Elliot and Messrs. Lapworth and Wilson a few fossils of Cambrian age.