. A dictionary of birds . ve had 3 free metacarpals,and 3 free digits, with 2, 3 and 4 phalanges respectively. 86o SKELETON much aborted digit seems in embryonic Ostriches to bear a claw(page 89). In the Sphenisci the pollex is more or less completelyfused with the index, which latter is made up of two long pha-langes, while the third digit consists of one long phalanx. Casiuirius,Dromseus and Apteryx retain only the index, the first and thirddisiits beinii; either lost or reduced to insi2;nificant traces.^ The Pelvic Arch is the portion of the pelvis (page 703)which is made up of the ilium (p
. A dictionary of birds . ve had 3 free metacarpals,and 3 free digits, with 2, 3 and 4 phalanges respectively. 86o SKELETON much aborted digit seems in embryonic Ostriches to bear a claw(page 89). In the Sphenisci the pollex is more or less completelyfused with the index, which latter is made up of two long pha-langes, while the third digit consists of one long phalanx. Casiuirius,Dromseus and Apteryx retain only the index, the first and thirddisiits beinii; either lost or reduced to insi2;nificant traces.^ The Pelvic Arch is the portion of the pelvis (page 703)which is made up of the ilium (page 458), ischium (page 460) andOS pubis (page 748), the last three being paired bones which meeton each side at the acetabulum or cup that receives the head of theFEMUR (page 248), coalescing with each other at an early ilium may be conveniently divided into a praeacetabular anda postacetabular part, the relative proportions of which afford someuseful characters ; thus in the Gallinai they are nearly equal, but. Common Fowl, Embryo and Acetabulum ; Foramen iscliiadicum ; Processus pectinealis. in the Accipitres the anterior is longest, while in Col//mhis, wheremost of the pelvis is drawn out backward, it is only half the lengthof the posterior. To the inner surface of the ilium, and in mostcases near its ventral margin, are attached the lateral processes ofthe cruro-sacral vertebrae (page 855), while near its dorsal rim isattached all the rest of the sacrum. The outer surface of thepraeacetabular portion forms a broad vertical blade with a more orless deep concavity which serves for the origin of the externaliliac muscles (often mistakenly called glutaeal). In rare cases theright and left pr?eacetabular portions fuse with each other alongtheir dorsal edge above the spinous processes of the neighbour-ing vertebrae and enclose a canal on each side. In front of the ^ As an appendix to the account of tliis part of the Skeleton, mention shouldhere be
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Keywords: ., bookauthorlyde, bookcentury1800, bookdecade1890, booksubjectbirds
