Fig. 2

Selected transversal paraffin sections of the prosoma of Galeodes turkestanus, sorted from anterior to posterior. a Anterior synganglion with neuromeres of the proto- (PC), deuto- (DC), and tritocerebrum (TC). In the soma cortex, smaller and denser nuclei of the globuli cells supply the mushroom body. In the pedipalpal neuromere (TC), single glomerular neuropils are present (asterisks). a–d Two mushroom body hafts projecting posteriad are associated with the dorsally located mushroom body neuropil. Further posterior, both mushroom body hafts converge into the main haft. a, b The projection neuron tract (white arrows) projects dorsad to innervate the mushroom body neuropil. b–d The second order visual neuropil is embedded in the dorsal cortex. b–e The malleolar neuropil is composed of distinct glomerular neuropil parcels and ensheathed by a thin layer of somata (white arrow in C; see also Fig. 6a). e, f The arcuate body is located in the posterodorsal protocerebrum and subdivided into two lobes. f Paired axon bundles from the malleolar receptor neurons (neurite projection) are separated and ensheathed by soma cortex. The arcuate body is accompanied ventrally by a small, sickle-shaped domain (ventral domain). In this section, only the anterior parts are visible (further posterior the domain fuses medially; compare Fig. 3b, c). Abbreviations: ab arcuate body, co soma cortex, DC deutocerebrum (cheliceral ganglion), es esophagus, gc globuli cells, h1 mushroom body haft 1, h2 mushroom body haft 2, mb mushroom body, mbn mushroom body neuropil, mh mushroom body main haft, mn malleolar neuropil, PC protocerebrum, TC tritocerebrum (pedipalpal ganglion), vd ventral domain, vn2 second order visual neuropil, VNC ventral nerve cord, wl1n neuromere associated with the first walking leg. Scale bars = 200 μm