P. ocellata.
2. Chitonellus. Two species.
Formerly classed with the Chiton; but as the testaceous plates of this genus are never joined, the two may be easily distinguished.
Shell elongated, multivalve; alternate pieces generally longitudinal; sides naked.
Chitonellus striatus.
Chitonellus larvæformis.
C. striatus. The striated Chitonellus.
Striæ radiating from the apex of each valve; margin serrated; base of the last valve obtuse.
C. larvæformis. The Caterpillar Chitonellus.
More or less cylindrical, almost naked; the valves of the shell very small, and almost entirely concealed under the skin; tufts hairy or silky between the parts of the valves near the margin.