Note: In the Spongi[ae], the soft sarcode of the body is
usually supported by a skeleton consisting of horny
fibers, or of silleceous or calcareous spicules. The
common sponges contain larger and smaller cavities and
canals, and numerous small ampull[ae] which which are
lined with ciliated cells capable of taking in solid
food. The outer surface usually has minute pores
through which water enters, and large openings for its
exit. Sponges produce eggs and spermatozoa, and the egg
when fertilized undergoes segmentation to form a
ciliated embryo.