Loganoceras, named by Foerste in 1921, (K284) has a circular cross section and an empty siphuncle ventral of the center.

Both are strongly curved with a notable rate of expansion; ventral sides, as with the previous genera, are on the outside, convex curvature, making them, again, exogastric.

Oocerina (K288), named by Foerste, 1926, is a slender, exogastric genus, like Oonoceras, from the Upper Silurian of Europe, Russia and possibly North America.

Paroocerina (K288), named by Zhurevleva in 1961, is a slender oncoceratid from the Middle and Upper Silurian of eastern Europe and ex-USSR (Russia), similar to Oocerina, but with a hyponomic sinus.

A close relationship may also be inferred between the primarily Silurian genera from Europe, including Russia; Oonoceras, Oocerina and Paroocerina, which are very similar in overall form.

The slender type oncoceratids give way to the strongly compressed Digenuoceras with sharply acute dorsum and venter, and to the more conical Miamiceras and Rizoceras.