Fig. 4

Galathowenia oculata. Cerebral eye, PSCs. TEM. a) Enlargement of the boxed area from Fig. 3c, ventral group of PSCs (psc) facing the brain with densely packed pigment granules (pg) extending to the apical membrane; b) Medial and dorsal group of PSCs (psc) with pigment-free bubble-like apices (asterisks), processes of PRCs (prc) terminating between apices of PSCs; inset: apex of PSC with residual cilium (ci); c) Apices of dorsal PSCs, bubble-like swellings extend above the level of junctional complexes (za), sensory microvilli (smv) form layer above and between PSCs apices; d, e) Apical regions of PSCs with bundles of intermediate filaments (if) terminating in small hemidesmosomes (arrows). Abbreviations: ci cilium of PSC, cu cuticle, if intermediate filaments, mv microvillus, np nucleus of PSC, pg pigment granule, prc PRC, psc PSC, smv sensory microvilli, za zonula adherens