C. mirifica, which is known only from the Canary Islands and the Azores, reaches a maximum size of about 30mm. It has been taken at a depth of 2000-2800m. It is a very distinctive species with convex whorls which are angled below the suture. The suture is very deep. The numerous costae are low and there are at least 10 spiral threads per whorl. The outer lip is thin and the aperture is oval.