Diagnosis. Domichnia originated by boring a single, circular opening through exozonal skeleton, followed by removal of endozonal skeleton to produce dwelling chambers. Chambers of varying shapes, linear, clavate, flabellate or irregular, ratherroughly, mechanically excavated out of endozonal skeleton in both ramose-twig or frondose-blade growth forms of Paleozoic Bryozoa. Characteristics of openings and chambers as presently known are those of the type species.

Sanctum Erickson and Bouchard, 2003 is a roughly clavate, irregular boring excavated in the weakly-skeletonized endozones of trepostome bryozoans. It was emended by Wyse Jackson and Key (2007) to include the possibility of two openings.

Unbranched, branched, clavate.

Category of architectural design: 2.66. Clavate-shaped borings.