A treatise on zoology . rebrain; for, foramen ; hb, habenular ganglion ; hp,hypophysial plate ; hy, hyoid region ; , gasseriau ganglion ; gl, glossopharyngeal; lb, labialcartilage ; mb, midbrain ; md, medulla ; , nasal capsule ; , nerve-cord ; nt, notochord; ol,olfactory lobe; ophtli, ophthalmic l)ranch of trigeminal nerve; pi, palatine, and pq, quadrate regions ; sob, suborbital nerve; sp, spinal nerve ; (i-S, branclies of trigeminal ; tr,trabecula cranii; ts, preorbital sensory bitinch ; v, vagus nerve ; , ventral root of spinalnerve ; 1, 2, 3, 4, cartilages of the tentacles. Fo
A treatise on zoology . rebrain; for, foramen ; hb, habenular ganglion ; hp,hypophysial plate ; hy, hyoid region ; , gasseriau ganglion ; gl, glossopharyngeal; lb, labialcartilage ; mb, midbrain ; md, medulla ; , nasal capsule ; , nerve-cord ; nt, notochord; ol,olfactory lobe; ophtli, ophthalmic l)ranch of trigeminal nerve; pi, palatine, and pq, quadrate regions ; sob, suborbital nerve; sp, spinal nerve ; (i-S, branclies of trigeminal ; tr,trabecula cranii; ts, preorbital sensory bitinch ; v, vagus nerve ; , ventral root of spinalnerve ; 1, 2, 3, 4, cartilages of the tentacles. For the nerves compare Figs. 22 and 25. of which joins the cartilage of the tongue below. Vestigialcartilages are also found near the branchial external openings,whether these are separate as in Bdellostoma or united as in Myxine(Figs. 23, 27). The huge rasping organ is provided with a set of large anterior 36 CVCLOSTOMATA and two small posterior cartilages, while a special plate supportsthe rows of horny teeth (Fig. 23).. c ou,S or 3 i ^=5 -5 ^ B •S-S, .5; 8 =« * ^ ^ 2 ^.2 >-. £ S ;i CI I* C5 ^^^ r; ,^ w •r^ --^ -r; -_ SI f^ ^ -E i;J: « °.5 ••??? Ilii- ort £ 2 & S ^ S ? Many attempts have been made to compare the skull andvisceral skeleton of the Cyclostome Avith those of the Gnathostome ;but none of these has j)roved very successful in detail. The com- SKELETON 37 parison of the lateral cranial barswith the trabecnlae, originallymade by Agassiz \\\ is doubtlesswell founded. Whilst Midler saAVthe mandibular arch representedin the subocular bar, and thehyoid in the styloid process,cornual, and median ventral styli-form cartilages, Huxley [229]considered the latter to be man-dibular, and the lingual to belongto the hyoid arch. The annularand corresponding cartilages inMi/xine are generally comparedto the labials, and the suboculararch to the branches of the trigeminalnerve pass below the suboculararch, not above as they shouldif this arch were
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Keywords: ., bookcentury1900, bookdecade1900, bookpublishe, booksubjectzoology
