Ehrenberg, 1847, emend. Petrushevskaya, 1971
The skeleton is represented by a well-developed D-shaped sagittal ring (median bar and anastomosed vertical and apical spines), either free (Zygocircus productus ov) or embedded into the latticed cephalic wall, in which case the cephalis is usually bilaterally lobed (Phormospyris stabilis scaphipes; Triceraspyris antarctica; Lophospyris pentagona pentagona). Sometimes with thorax, abdomen always absent. The typical heteropolar nassellarian symmetry is often inconspicuous in the Spyridae.
The following species of this family are treated in the present volume:
Acanthodesmia viniculata
Amphispyris reticulata
Cephalospyris clathrobursa
Lophospyris pentagona
Nephrospyris renilla
Phormospyris stabilis
Tholospyris anthophora
Tholospyris ramosa
Tholospyris spp.
Tholospyris tripodiscus
Triceraspyris antarctica
Zygocircus productus