. Key to North American birds [microform] : containing a concise account of every species of living and fossil bird at present known from the continent north of the Mexican and United States boundary, inclusive of Greenland. Birds; Ornithology; Oiseaux; Ornithologie. 154 GENERAL OliNITHOLOGY. the exoccipital {teo). This trowel of cartilage is the upper anterior segmcut of the hyoidcan (second post-oral) arch, being to that arch what the pterygo-palatiuc bar is to the niandil)ular (first post-oralj ardi. Several parts of this stapedial cartilage are recognized, as named in the fine print under
. Key to North American birds [microform] : containing a concise account of every species of living and fossil bird at present known from the continent north of the Mexican and United States boundary, inclusive of Greenland. Birds; Ornithology; Oiseaux; Ornithologie. 154 GENERAL OliNITHOLOGY. the exoccipital {teo). This trowel of cartilage is the upper anterior segmcut of the hyoidcan (second post-oral) arch, being to that arch what the pterygo-palatiuc bar is to the niandil)ular (first post-oralj ardi. Several parts of this stapedial cartilage are recognized, as named in the fine print under the figure. If the connections of the second post-oral arch were completed, as those of tlio first are, the tongue bone would be slung to the skull as the lower jaw is; but they are not, the tract rep- resented by the dot-lino from the sti/lo-hyal, sth, to the cerato-hyal, chy, being, like ist, above sth, only soft connective tissue. This defect of connection is made up for by the great development of the hydideau parts of the third post-oral arch, br 1 and br 2, wliich retain the tongue-bone in position, without however articulating it with the skull. The hand of the trowel of cartilage soon segments itself off from tiie ear-ca)i- sule, bringing jvway with it a small oval piece of tlie periot;y wall, which piece is the true stapes, and tlio oval space in which it fits is tho fenestra ovalis hiuVmii. Fio. fi7. —Tho post-oral arches of tho Iiouse inartiii, at middle of period of Incuba- tion, lateral view, x 14 diameters, mk, stump of mcckellan or mandibular rod. its articular j^to ^1,^ inmost ear (the COChlea). The broad part (if part, (ic, already sliapcn I o, quadrate bone, or ., ^ i i i j • ^i ^ ^ i- i ^ i. i sHspensorluni of lower jaw, with a free anterior the trowel-blade IS the extra-stapedial part, on which orbital process and loiiR posterior otic process t],(> mewbrana ttjmpani, or ear-druui, will be stretclied, articulating with the ear-c.; .mle, of which/CO, ..
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbirds, bookyear1884
