Fig. 3. The optic peduncle of the right eyestalk. (A) Lateral view. This side shows the front of the crab. (B) Ventral view. The arrowhead shows the front of the crab. The dotted lines indicate the boundaries between the frontal, middle and posterior regions of the MT. Abbreviations: MT, medulla terminalis; nsc, cluster of neurosecretory cells; f, frontal region of the MT; m, middle region of the MT; p, posterior region of the MT; BA, base of the optic peduncle; TC, transverse cut of the MT; DC, dorsal-half cut of the MT; VC, ventral-half cut of the MT.