Chalice corals are not corals of a single species, from a single genus or even from a single family. Instead, the term chalice is often used to refer to a growth form that resembles a cup or chalice. Many different species of coral within different genera and even different families display this growth form.
Most of the popular chalice corals come from the Family Pectiniidae, which is currently composed of at least six genera.
"¢Echinophyllia
"¢Mycedium"¢Oxypora
"¢Pectinia
"¢Physophyllia
"¢Echinomorpha
These are all stony corals, and they are commonly referred to by hobbyists as chalice, scroll, elephant nose, peacock, lettuce, plate, antler, palm, and hibiscus coral. Most commonly seen in the hobby are colorful, slow-growing animals. All the known species are zooxanthellate, which means they host symbiotic algae within their tissue. Many are considered fairly hardy and should do well in an established stable tropical reef aquarium.
Oxypora spp.
The most common and well-known of the chalice corals are those from the genus Oxypora. These often have stunning spirals of wafer-thin plates rising from their thick base. Large irregularly spaced corallites are visible, and it's from these corallites that the animal's polyps and stinging sweeper tentacles emerge. It is important to give this animal an ample buffer zone so it does not sting other sessile invertebrates. These corals do best with brighter lighting and lower flow situations, although like most corals in the family, they are quite tolerant of a wide range of conditions.
Genus Mycedium
Oxypora species are frequently confused with corals from the genus Mycedium. While both may be called chalice corals, Mycedium species are more commonly called elephant nose coral or peacock coral. The corallites of Mycedium species angle toward the outer perimeter of the coral, and this is the easiest way to tell the difference between the two. In addition to their stinging sweeper tentacles, Mycedium species can release toxins into the water as a means of competing with neighboring corals, especially soft corals. Mycedium species are fairly tolerant of varying degrees of lighting and current, and deep water varieties can also do well in low light and shaded situations.
Pic on left looks to be a crappy pic.. but said to be Oxypora sp.
Online ID's from other expert reefers even seem to be a bit confusing...