No elongated tail.
Genus Second. Asaphus.
Body broad and rather flat. Middle lobe prominent and very distinct.
Flanks or lateral lobes each double the size of the middle lobe.
Submembranaceous expansions extending beyond the lateral lobes.
Buckler semicircular, with two reticulated eye-shaped tubercles.
Abdomen divided into 8 or 12 articulations.
Genus Third. Ogygia.
Body much depressed into an oblong ellipsis not contractile into a sphere.
Buckler edged, a slight longitudinal furrow arising from its anterior extremity. Posterior angles elongated into points.