Ribs without uncinate processes.
In these forms the bundles of setae are either capilliform or uncinate, and the dorsal setae of the thorax are like the ventral setae of the abdomen.
The peristomium has no setae, and the setae generally are hair-like or uncinate, often forming almost complete rings.
(iv.) Trophi uncinate: Flosculariaceae; disk a contractile cup, often lobed, the cingulum of long vibratile cilia, of very long motionless bristles or absent, rarely with an outer zone of fine cilia.
Oral funnel produced into a fine tube hanging freely into a pharyngeal cup, containing the uncinate trophi.
The cervical and thoracic vertebrae seem to be biconcave; the cervical ribs are much reduced and were apparently still movable; the thoracic ribs are devoid of uncinate processes.