Definitions for "Siphuncle"
The tube which runs through the partitions of chambered cephalopod shells.
Living cord which connects all the chambers in septate shells. Synapomorphy of the Cephalopoda.
The Siphuncle is a tube - which may be thick or slender - which runs through each of the internal chambers ( camerae) of the shell, from the base of the living chamber to the apex. It consists of soft and shelly parts, including septal necks, connecting rings, calcareous deposits, and siphuncular cord. Nautiloids are classified by the nature of the siphuncle and its position within the shell.