Haeckel, 1881
The major part of the shell is composed of a series of successively larger elliptical latticed girdles in three mutually perpendicular planes, with the major diameter of each girdle being the minor diameter of the next larger one (P. clevei intro). The center is occupied by a small ellipsoidal structure — the microsphere (see Dumitrica, 1989).
The following species of this family are treated in the present volume:
Dipylissa bensoni
Octopyle stenozona
Phorticium clevei
Pylolena armata