The Proximal End of Cryptograptus

Abstract

It has long been suspected that the mode of development of the proximal end in Cryptograptus may differ considerably from the ordinary Diplograptid type, but the preservation of the material has hitherto been too poor to allow of a complete interpretation. Amongst the graptolites preserved in impure limestone nodules1 in the Balclatchie Shales at Laggan Burn, near Girvan, Cryptograptus tricornis is abundant, and despite the extreme tenuity of the periderm, specimens can be dissolved out with HC1 and HF, in a remarkably good state of preservation.