The four or five coccygeal bones curve forwards from the inferior extremity of the pelvis. They are reduced to little more than the central element of a vertebra. The first piece is attached to the last bone of the sacrum by two cornua, which represent the neurapophyses, unconnected by a neural spine. The first coccygeal piece is often separate; the three succeeding ones are usually confluent, and form an elongated knotted cylinder.
* Archetype and Homologies, p. 159.