Note 119 — 5. Genus—PYRGOMA.

From external aspect I suspect this species to be the Creusia madreporarum, Leach (?), as given in Chenu, ‘Illust. Conch.,’ Tab. 1, fig. 6. But I feel sure that Leach has nowhere published this name; and it may be observed that Chenu gives it with a mark of doubt. The shell in its imbedded state is only figured; the opercular valves are not given; and no descriptive details are added. Under these circumstances I have not adopted this name; I have, perhaps, been in some degree influenced by the fact that this species, judging from the many specimens examined by me, is never imbedded in madrepores, but exclusively in millepores, so that Chenu or Leach’s specific name of Madreporarum is singularly inappropriate.