VD1/RPD2 α-neuropeptide-lir structures in an early larva of Lineus albocinctus . Apical faces upwards in both aspects. (A) Maximum projection of a scan through the entire specimen VD1/RPD2 α-neuropeptide-lir is shown in graded scales of dark red to bright yellow, cell nuclei are shown in blue. The oral nerve ring encircles the junction between the esophagus and the stomach. Two suboral neurites descend from the oral nerve ring towards the transition between the posterior and the lateral lobes. The anterior and the posterior lobes are underlain by two marginal neurite bundles. The inner marginal neurite bundle splits into two separate neurite bundles at the transition of the lobes. (B) VD1/RPD2 α-neuropeptide-lir structures are shown in red. All scale bars equal 100 μm. Abbreviations: *, mouth; ap, apical plate; cb, ciliary band; cd, cephalic disc; es, esophagus; imb, inner marginal neurite bundle; omb, outer marginal neurite bundle; onr, oral nerve ring; son, suboral neurite; st, stomach; td, trunk disc.