Each pair of branches (stipes) curve away sharply from the ends of the funicle then run more or less parallel with each other at a distance of 5 to 8 mm (0.20 to 0.31 in) apart.

[3][4] It was first described by the British paleontologist Henry Alleyne Nicholson in 1873 from specimens recovered from Lévis, Quebec, Canada.

It has been identified in graptoliferous rocks from Australia, New Zealand, Canada (Newfoundland), the United States (Texas), Kazakhstan, Russia (Taimyr), China, South America, Norway, and Sweden.

It is unknown, however, in areas which lack coeval graptoliferous rocks like the United Kingdom, Spitsbergen, and Africa.

Its first appearance at the GSSP section of the Diabasbrottet Quarry in Västergötland, Sweden is defined as the beginning of the Floian Age (477.1 million years ago) of the Ordovician.