Disarticulated valves, dorsal surface. Length of live animal 14.5 mm. North Yorkshire. September 2014. (leg. Paula Lightfoot).
Valves lose vibrancy of colour immediately upon death, or even before if in poor condition or injured. Chemical stability of different pigments varies; reds persist while pale greens soon fade, as in this image.
Valves numbered head to tail as i-viii.
1: semicircular head valve (i).
2: head valve (i), image enlarged, semicircular, concentric growth lines centred on origin on posterior edge.
3: less than semicircular tail valve (viii), almost twice as wide as long.
4: tail valve (viii) enlarged & tilted forwards to reveal insertion plates.
5: antemedian mucro, origin of surrounding concentric growth lines.
6: steep, slightly convex, postmucronal slope.
7-7-5: central antemucronal area resembles jugal area of intermediate valves.
8-8-8: triangular jugal area of intermediate valve (iii).

KEY ID FEATURES and similar species at: 01 Boreochiton ruber. Length 12mm. North Yorkshire. September 2014. (leg. Paula Lightfoot).