IV.—On Scottish Monograptidæ

This genus was founded by Mr. Carruthers to include those compound forms of monoprionidian Graptolites in which the polypary is unilateral, growing from the initial point in one direction only. There can be no hesitation in regarding it morphologically as a branching Monograptus; its mode of development, the characters of its hydrothecae, and its geological distribution, all pointing unmistakably in this direction.