1	Corallites arrangement procoid, cerioid or meandroid, width of primary septa clearly thicker than secondary septa	P.russelli
–	Corallites arrangement cerioid or meandroid, width of primary septa not clearly thicker than secondary septa	2
2	Corallites arrangement of meandroid dominant	P.australensis
–	Corallites arrangement cerioid dominant, meandroid rare	3
3	Groove-and-tube structure present on joint of corallite walls	P.deformis
–	Groove-and-tube structure absent on joint of corallite walls	P.variabilis sp. nov.