Order Aglaspina Walcott.
Body trilobite-like, with few thoracic segments, and a spine-like telson. Appendages biramous.
Family Aglaspidæ Clarke.
Cephalon trilobate, with or without compound eyes, seven or eight segments in the thorax.
Genus Aglaspis Hall.
Compound eyes present, seven segments in thorax. Upper Cambrian, Wisconsin.
Genus Molaria Walcott.
Compound eyes absent, eight segments in thorax. Middle Cambrian, British Columbia.
Genus Habelia Walcott.
Compound eyes absent. Not yet fully described. Middle Cambrian, British Columbia.