. A history of British birds, indigenous and migratory: including their organization, habits, and relations; remarks on classification and nomenclature; an account of the principal organs of birds, and observations relative to practical ornithology .. . Tnpanic bone, and theelasticity of the parts at the junction of the frontal and nasalbones, allows the upper mandible a degree of motion varyingin the different families. The lower jaw of an adult bird isformed of a single bone, having the sides generally thin andnearly vertical, and articulated to the tympanic bone. Fig. 1 representsthe skull
. A history of British birds, indigenous and migratory: including their organization, habits, and relations; remarks on classification and nomenclature; an account of the principal organs of birds, and observations relative to practical ornithology .. . Tnpanic bone, and theelasticity of the parts at the junction of the frontal and nasalbones, allows the upper mandible a degree of motion varyingin the different families. The lower jaw of an adult bird isformed of a single bone, having the sides generally thin andnearly vertical, and articulated to the tympanic bone. Fig. 1 representsthe skull of the Ra-ven, Cortus Cor ax ^viewed laterally. Theoccipital bone,«, ori-ginally composed ofFig. 1. Skull of Raven. f^^j. pieces, the an- terior or basilar; the posterior, spinous, or superior; andthe two lateral or condyloid. The temporal bone is com-posed of the petrous portion, b, containing the ear ; the. 22 INTRODUCTION. squamous portion, c ; to which is articulated the tympanicportion, or os quadratum, d. The parietal bone, e, intervenesbetween the occipital and the frontal. The latter, /, besidesforming the anterior part of the covering of the brain, alsoconstitutes the upper edge of the orbit or cavity in which theeye is lodged, its posterior process, ^, bounding it behind, whileits antorbital process, /i, margins it before, and is connectedwith the lachrpiial bones. The lower part of the orbit isthus left incomplete, as it is in various degrees in all birds, ex-cepting some of the parrots. The sphenoid bone is originallycomposed of several distinct parts: a basilar portion, united tothat of the occipital bone; two orbital plates, /, constitutingpart of the orbits and of their septum; two cranial plates, /,corresponding to the wings, and forming the posterior part ofthe orbits; and two pterygoid or interarticular portions, k,which are articulated posteriorly to the tympanic
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Keywords: ., bo, bookcentury1800, bookdecade1830, booksubjectbirdsgreatbritain
