Diagnosis: Boring in carbonate substrate comprising a single chamber or networks or boxworks of chambers or non-camerate galleries, connected to the substrate surface by several or numerous apertures. The galleries show increase in size during growth; in some forms, inflation at more or less regular distances produces a system of closely interconnected chambers; in other forms chambers lie distant from one other; in still other forms no cameration develops. The boring surface of most forms bears a cuspate microsculpture. Fine pioneer (exploratory) threads are usually present, arising from all or some surfaces of the system. Apertural canals lead to apertures (in- and exhalent pores). [Emended diagnosis taken from Bromley et al., 2009]
2.72. Camerate boxwork borings
Diagnosis. A single, large, spheroidal to ovoidal-subpolygonal chamber bearing sparse, radiating, simple, fairly straight, unbranched canals that are shorter than the diameter of the chamber. A crown of apertures is present along the peripheral area of the chamber.
Remark: Single or numerous chambers excavated in calcareous substrates; connected to surface by apertures. Made at the present day by clionid sponges.