Some definitions

arthropods-Any of numerous invertebrate animals of the phylum Arthropoda, including the insects, crustaceans, arachnids, and myriapods, that are characterized by a chitinous exoskeleton and a segmented body to which jointed appendages are articulated in pairs. ETYMOLOGY: From New Latin Arthropoda, phylum name : arthro– + New Latin -poda, -pod.

cephalopods-Any of various marine mollusks of the class Cephalopoda, such as the octopus, squid, cuttlefish, or nautilus, having a large head, large eyes, prehensile tentacles, and, in most species, an ink sac containing a dark fluid used for protection or defense. ADJECTIVE: Of, relating to, or belonging to the class Cephalopoda. ETYMOLOGY: From New Latin Cephalopoda, class name : cephalo– + -poda, -pod.

molluscs-Any of numerous chiefly marine invertebrates of the phylum Mollusca, typically having a soft unsegmented body, a mantle, and a protective calcareous shell and including the edible shellfish and the snails. ETYMOLOGY: French mollusque, from New Latin Mollusca, phylum name, from neuter pl. of Latin molluscus, thin-shelled, from mollis, soft. See mel-1 in Appendix I.

rhabdomeric
ciliary
platyneris dumerilii (ragworm)