Length 29 mm when live. LWS. Isle of Lewis, Scotland. April 2018. Leg. D.M. McKay & S.Taylor.
Girdle and body removed except the transverse muscles which connect the valves.
As with chitons generally, T. marmorea has eight overlapping valves; i = head valve, viii = tail valve.
Left: The upper layer, ‘tegmentum’, is made of coloured aragonite.
Right: The lower layer, ‘articulamentum’, is made of white aragonite, sometimes with a pink jugal tract (1). The anterior of the articulamentum on valves ii to viii has curved extensions called apophyses (2). They underlie the next valve forwards and are connected to it by the transverse muscle. The valves in the image are articulated as in life because the transverse muscles have been left intact except that connecting valves ii and iii.