Fig. 3. Schematic diagram showing the beaks and musculature of Octopus
bimaculoides. (A) The beaks and musculature of a complete buccal mass.
(B) The upper beak and lower beak separated to show the underlying muscles.
(C) The beaks and musculature separated to show the shape of the beaks and the
shape of the individual muscles. AMM, anterior mandibular muscle (yellow);
LMM, lateral mandibular muscle (purple); PMM, posterior mandibular muscle
(blue); SMM, superior mandibular muscle (green).