Cerebrum, Schroder, Medioli & Scott, 1989

Beutel Dominique Zimmermann Marcus Krauss Susanne Randolf Benjamin Wipfler, Rolf G., 2010, Head morphology of Osmylus fulvicephalus (Osmylidae, Neuroptera) and its phylogenetic implications, Organisms Diversity & Evolution (New York, N. Y.) 10 (4), pp. 311-329 : 321

Cerebrum , suboesophageal complex and stomatogastric nervous system ( Figs. 3a–d ; 8b, c ; 9a )

About one third of the lumen of the head capsule is occupied by the brain and suboesophageal ganglion. The proto-, deuto- and tritocerebrum form a compact structural unit. The protocerebral part appears dumbbell-shaped due to the presence of large optical lobes ( Figs. 3c, d ; 8c : pcer). The nerves of the three ocelli originate dorsally; a thin nervus connectivus originates medially on the frontal side ( Figs. 3a–d , 8c : noc, ncon). The parallel antennal nerves ( Fig. 3a–d : nan) originate from the distinctly protruding deutocerebral part ( Figs. 3c ; 8b : dcer). The circumoesophageal connectives are continuous with the cone-shaped tritocerebrum. A separate tritocerebral commissure is present. The ovoid suboesophageal complex lies anterior to and below the tentorial bridge ( Figs. 3d ; 8c ; 9a : soeg). The frontal ganglion above the anatomical mouth has a triangular shape ( Figs. 3c ; 8a : fg). It is connected with the protocerebrum by the unpaired nervus connectivus, and with the tritocerebrum by the frontal connectives ( Fig. 3c : ncon, fcon). All three connecting nerves are distinctly curved. The nervus frontalis and the nervus recurrens ( Fig. 3c : nrec) orginate on the anterior and posterior apex of the frontal ganglion, respectively.

Figures

Fig. 3 Osmylus fulvicephalus, head, three-dimensional reconstructions. a Frontal view, including right half of head capsule. b Lateral view of brain, tracheae and selected muscles. c Anterolateral view of brain, tentorium and selected muscles. d Anterolateral (nearly lateral) view of brain and selected muscles. Labels: ata=anterior tentorial arm, dcer=deuterocerebrum, dta=dorsal tentorial arm, fcon=frontal connective, fg=ganglion frontale, nan=antennal nerve (right antennal nerve obliterated in specimen used for microtome sectioning), ncon= nervus connectivus, noc=ocellar nerve (median ocellar nerve obliterated in specimen used for microtome sectioning), nrec=nervus

Fig. 8 Osmylus fulvicephalus, head, cross sections. a Level of ganglion frontale. b Level of compound eye. c Level of brain. Labels: alb=anterior labium, ata=anterior tentorial arm, cl=clypeus, con= condyle (primary joint), dcer=deuterocerebrum, md=mandible, mdg= mandibular gland, noc=ocellar nerve, oc = ocellus, onp=optic neuropils, pcer=protocerebrum, ph=pharynx, sc=scapus, smj=secondary mandibular joint, soeg=suboesophageal ganglion, 1=M. tentorioscapalis anterior, 2=M. tentorioscapalis posterior, 6 = M. scapopedicellaris medialis, 9 =M. frontoepipharyngalis, 12 =M. craniomandibularis externus, 17=M. tentoriocardinalis, 18=M. tentoriostipitalis, 23=M. stipitopalpalis internus, 29=M. tentoriopraementalis inferior, 34= praementopalpalis externus, 41a, b=M. frontohypopharyngalis, 44= M. clypeobuccalis, 46=M. frontobuccalis posterior, 67=M. transversalis buccae

Fig. 9 Osmylus fulvicephalus, head, cross sections. a Level of subosephageal ganglion. b Level of posterior labium. c Level of cervix. Labels: oes=oesophagus, ph=pharynx, soeg=suboesophageal ganglion, tb=tentorial bridge, tr=tracheae, 11=M. craniomandibularis internus, 12=M. craniomandibularis externus, 17=M. tentoriocardinalis, 18=M. tentoriostipitalis, 20=M. stipitolacinialis, 28=M. submentopraementalis, 29=M. tentoriopraementalis inferior, 42 =M. tentoriohypopharyngalis, 51=M. verticopharyngalis