The Calcinea are a subclass of the

calcareous sponge The calcareous sponges or calcereans are sponges that make up the class Calcarea, characterized by spicules made of calcium carbonate in the form of high-magnesium calcite or aragonite. While the spicules in most species are triradiate (with three ...

s. Its phylum is Porifera and class is Calcarea. Branching is usually

dichotomous A dichotomy () is a partition of a set, partition of a whole (or a set) into two parts (subsets). In other words, this couple of parts must be * jointly exhaustive: everything must belong to one part or the other, and * mutually exclusive: nothi ...

or umbellate with

anastomoses An anastomosis (, : anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf#Veins, leaf veins, or streams. Such a connection may be ...

, which gives rise to reticulate growths on stalks in adults. Most varieties are coral red or sulphur yellow.The Skeleton and Classification of Calcareous Sponges
, Retrieved 2-25-2016

References

Sponge subclasses {{Calcarea-stub