Phalacromina Phalagnostus is a genus of small trilobites, in the order Agnostida.

It lived during the Middle Cambrian, in what are now Canada (Newfoundland and Northwest Territories), China, the Czech Republic, Denmark, England, France, the Russian Federation (Bennett Island, Yakutia), Wales, Sweden, and possibly the United States (Vermont).

The pygidium is also very effaced, but the ovate pygidial axis (or rhachis) is well defined and a border furrow is also present.

[3] Due to the high level of effacement, establishing the relationship of Phalagnostus to other Agnostoidea is difficult.

The rhachis is circular to ovate, clearly defined by deep axial furrows.