Cirquella is an extinct genus from a well-known class of fossil marine arthropods, the trilobites.
[3] Only the thin and lightly calcified headshields (or cephalon) of Cirquella have ever been found.
[3] In Cirquella espinata there is no genal spine but a slight angularity of margin opposite first lobe in front of the occipital ring.
[4] C. nummularia is known from the earliest half of the Lower Nevadella Zone, in the Dogtooth Mountains, British Columbia, Canada, and in Nevada.
[4] C. nelsoni is reported from the Fallotaspis-Judomia Faunule, Fallotaspis Biozone, Campito Formation, Inyo-White Mountains, Eastern California.