chitonidæ

from The Century Dictionary.

• A family of gastropodous mollusks, the chitons, the anomalous character of which has caused them to be classed as a suborder, Polyplacophora, or as a group of a higher grade, Amphomæa. They differ from all other mollusks in having a bilaterally symmetrical body covered with a number (in typical forms 8) of separate overlapping plates or valves, thus exhibiting the nearest approach to the vermiform or articulated type of structure. There are no eyes and no tentacles, and the gills and kidneys are paired. The species are numerous, and are found all over the world adhering to rocks like limpets. The leading genera are Chiton and Cryptoplax. Also called Chitonacea.