Cephalopoda is a class of Phylum mollusca. They are the squids and octopuses. They are the highest in organization in that division of the animal kingdom, characterized by having the organs of prehension and locomotion, called tentacles or arms, attached to the head. The arms are furnished with numerous suckers, and enable them to cling to and entangle their prey;
and they have a pair of well-developed jaws and eyes. They are divided into two sections, Tetrabranchiata (four-gilled) and Dibranchiata (two-gilled). The nautilus and the fossil genera Orthoceras, Ammonites, Goniatites, etc, belong to the Tetrabranchiata, in which the animal has an external shell. The dibranchiate group includes the argonaut, the octopus or eight-armed cuttlefishes, and the ten-armed forms, as the squids, the fossil belenmites, etc. The shell is in all these internal (being known as the 'pen' and the 'cuttle-bone'), in some rudimentary. The fossil Cephalopoda are multitudinous. Research Cephalopoda
Abbreviations
Nature
Research Cephalopoda