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Show 184 MR. R. H. BURNE ON THE [Mai*. 5, PLATE XX. Fig. 1, Din ilysia patagonica (pp. 176-179); imperfect skull and mandible, upper and left lateral (la) aspects, with oral aspect of right maxilla (lb) and fractured quadrate bone (le), nat. size.-From Red Sandstone, Neuquen. ag., angular ; d., dentary ; ec, ectopterygoid ; ex.occ, exoccipital; jr., frontal; mx., maxilla; ««., nasal; war., external narial opening ; o., projecting otic bone ; op., opisthotic; orb., orbit; pa., parietal; pr.f, prefrontal; pr.O., pro-otic; pt., pterygoid; pt.f., postfrontal; qu., quadrate ; r., lateral ridge on parietal; s.occ, supraoccipital; s.t., supratemporal ; x, fracture. 2. Ditto; portion of vertebral column of same specimen, nat. size. n., neural spine ; r., rib. All the original specimens are preserved in the L a Plata Museum. 2. Note on the Innervation of the Supraorbital Canal in the Cat-fish (Chimcera monstrosa). By R. H . B U R N E , B.A., F.Z.S., Anatomical Assistant in the M u s e u m of the Royal College of Surgeons. [Received February 1, 1901.] (Text-figure 49.) An excellent historical resume of the work that has hitherto been done upon the comparative anatomy and more particularly the innervation of the organs of the lateral line, with a discussion of the morphological conclusions that may be drawn from them, is to be found in two recent papers by Cole1, so that for the purposes of this note it will be amply sufficient to briefly sketch certain ascertained facts with regard to the innervation of this sensory system. It has now been shown in several instances that the nerves that supply the lateral-line organs have no real relation to the cranial nerves in whose company they leave the brain, but arise within the brain in common with the auditory nerve from a particular centre-the tuberculum acusticum. Furthermore in almost all cases, when sufficient care is used in the examination, the lateral-line nerves are found to enter into a definite and constant relationship with certain of the cranial nerves. Thus the lateral-line nerve that supplies the supraorbital canal forms the Ramus ophthalmicus superficialis of the Vllth cranial nerve, that for the suborbital canal constitutes the R. buccalis VII, and that for the hyomandibular canal the Ramus hyomandibularis VII; while the main lateral canal of the truuk is innervated by the lateralis branch of the vagus. Although this connection of the lateral-line nerves with the Vllth aud Xth cranial nerves only is almost universal, it is uot so in every case. For instance, iu many 1 Cole: "Observations on the Structure and Morphology of the Cranial Nerves and Lateral Sense-organs of Fishes," Trans. Linn. Soc. vii. 1898, p. 187; and " O n the Cranial Nerves of Chinusra monstrosa," Trans. R, Soc. Edinb. xxxviii. 1897, p. 635. |
