Fig. 10

Syllis garciai. Brain and associated clusters of somata. a and b: Schemata of the anterior end of S. garciaig. Dotted lines indicate the position of the sections C, D and E. The neuropil of the brain is enveloped by somata (red). The nuchal lobes (green) are restricted to the achaetous segment. A pair of dorsal clusters of somata (turquoise) lie laterally to the brain. c: Semi-thin cross section of the brain, slightly oblique. Drcc and vrcc enter the brain. d: Semi-thin saggital section through the nuchal organ. Somata of primary receptor cells and somata of the brain are not distinguishable from each other. The nuchal lobes (green) extent posteriorly. e: Semi-thin cross section of the nuchal organ, slightly oblique. The prominent pair of nuchal lobes (green) lies dorsolaterally. Scale bars = 50 μm. Abbreviations: ae – anterior eye; bc – buccal cavity; bm – muscle penetrating the brain; br – brain; cc – circumoesophageal connective; ccp – cells of crescent shaped ciliary patch; cm – cirrus muscle; cun – cuticle of nuchal organ; dc – dorsal cirrus; dcs – dorsal cluster of somata; dcvr - dorsal commissure of vrcc; dlm – dorsal longitudinal muscles; drcc – dorsal root of circumoesophageal connective; es – eye spot; la – lateral antenna; ma – median antenna; no – nuchal organ; olc – olfactory chamber; pa – palp; pe – posterior eye; pn1–3 – palp neurote bundle 1–3; pon – posterior neurite bundle; stgn1–5 – stomatogastric neurite bundles 1–5; tc – tentacular cirrus; tcn – neurite bundle innervating tentacular cirrus; vlm – ventral longitudinal muscle; vnc – ventral nerve cord; vrcc – ventral root of circumoesophageal connective