Three dimensional brain reconstruction of Birgus latro. Only the left hemisphere of bilaterally paired neuropils and cell clusters is shown, when viewed from dorsal. The cell clusters shown in A, are left out in B, to display the ventral surface structure of neuropils and the neuropils of the medial protocerebrum. Numbers 5, 6, 10 and 9/11 (blue) identify cell clusters. Other abbreviations: AIINv, antenna II nerve; AcN, accessory neuropil; AnN, antenna II neuropil; CA, cerebral artery; CB, central body neuropil; CN, columnar neuropil, HN, hemiellipsoid neuropil; La, lamina; LAN, lateral antenna I neuropil; Lo, lobula; LoP, lobula plate; Me, medulla; MAN, median antenna I neuropil; mPC, medial protocerebrum; OC, oesophageal connective; OGT, olfactory globular tract; ON, olfactory neuropil (olfactory lobe); PB, protocerebral bridge; TM, terminal medulla.