Tectura virginea for comparison.
1: reddish band, on periphery of yellowish mantle-skirt, and corresponding pink ray on shell produced by it.
2: oval yellow sole.
3: yellowish mantle-skirt.
4: strong, white, bundle of shell-muscle; fully exposed on one side of U arrangement as limpet stretches to right itself.
5: gap between muscle bundles; route of blood vessel to efferent pallial vessel.
6: black eye on dorsum of base of tentacle barely visible ventrally through translucent tentacle.
7: tip of ctenidium protruding from nuchal cavity on right of limpet.
APPENDIX re range advance/retreat: flic.kr/p/2jW74ig