Main colour of flesh is white or pale yellowish white.
1 to 1: one side of the pedal-retractor muscle, a U of white muscle bundles separated by narrow gaps, that attaches the body/foot to the shell.
2: sole and sides of foot pale yellowish white on this specimen, often just white.
3: the tiny eye on the base of each tentacle dorsally is a deep, narrow pit, detectable in the translucent tentacle as a black line running in to a broader black spot. Some or all of the black may be pigmented retinal cells.
It can probably differentiate light from shade, and detect the direction of the light source, but cannot discern shapes. The eye is almost always concealed within the confines of the shell.
APPENDIX re range advance/retreat: flic.kr/p/2jW74ig