. On the anatomy of vertebrates [electronic resource] . ton forming the skull,with the light of the stage of developement manifested in animmature Mammal when a certain growth has proceeded from theseveral points of ossification established in the primordial mem-branous and cartilaginous basis, we find that the neural arch ofthe occipital vertebra, fig. 189, Ni, l, 2, and 3, agrees with that ofthe Bird and Crocodile in the connation of the diapophysis, 4,with the neurapophysis, 2; but the process, called ( paroccipital,now descends from the lower part of the arch, and, in manyMammals, is of gr
. On the anatomy of vertebrates [electronic resource] . ton forming the skull,with the light of the stage of developement manifested in animmature Mammal when a certain growth has proceeded from theseveral points of ossification established in the primordial mem-branous and cartilaginous basis, we find that the neural arch ofthe occipital vertebra, fig. 189, Ni, l, 2, and 3, agrees with that ofthe Bird and Crocodile in the connation of the diapophysis, 4,with the neurapophysis, 2; but the process, called ( paroccipital,now descends from the lower part of the arch, and, in manyMammals, is of great length. An articular condyle is developedfrom each neurapophysis, 2, which articulates with the concaveanterior zygapophysis of the atlas, and is the homotype of the OSSEOUS SYSTEM OF MAMMALIA. 301 posterior zygapophysis in the trunk-vertebra. The centrum, l,is reduced to a compressed plate, and its hinder articular surfaceis not more developed than is the front one of the centrum of theatlas, with which it is connected by ligament. The expanse of. Side view of cranial vertebra and appendages, Hog. the occipital spine, 3, has been governed by the superior develope-ment of the cerebellum in the Mammalian class. The haemal arch of the occipital vertebra is here represented,like those of the cervical vertebrae, by the pleurapophysial elementsonly; but these are developed into broad triangular plates withoutstanding processes: that called 6 spine, 51, is exogenous; butthat called ( coracoid is developed from an independent osseouscentre, which is a rudiment of the haemapophysis, coalesces withthe pleurapophysis, and, in the present class, only attains its nor-mal proportions, completing the arch at figs. 186, d, 187, 2, with thehaemal spine, ib. 9, in the Monotremes. The diverging appendage(fore-limb, 53-57) of this arch, though retaining the general fea-tures of its primitive radiated form, has been the seat of great de-velopement and much modification and adjustment of its di
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