Note:  Do not rely on this information. It is very old.


Holocystis, a genus of corals found in the Lower Greensand of the south of England. The genus is well-known, owing to the fact that the septa are arranged in multiples of four instead of six, and so it was for long included among the

Paleeozoic group, the Rugosa (q.v.). It is, however, now regarded as an ordinary Astrean coral.