Radula under high magnification of Scanning Electron Microscope (SEM). Barents Sea, Arctic. © B. Sirenko.
Left image magnified more than right one. 1000μm = 1 mm
Each row has 8 teeth on either side of the central tooth; total of 17.
1: the central (rhachidian) tooth is a reflexed, rectangular channel with a widened chisel-like terminal blade.
2: the minor (first) lateral tooth (2) is small and bladeless.
3: shaft base of major (second) lateral tooth (see image 35 Tonicella marmorea ).
4: broken shaft of major (second) lateral tooth.
5: first and second uncinal teeth are small and unobtrusive between the bases of the major lateral and major (third) uncinal tooth.
6: major (third) uncinal tooth; spatulate with head shaped and sculptured like a feather, probably used to sweep up cut food particles.
7: three low plates, marginal ‘teeth’, at the margin of the radula.

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