The ascending spur of the tibiale (? = astragalus) is present in Deinosauria. The bony arch confining the extensor tendons in the Pigeon as they pass over the tarsal region of the tibio-tarsus is ligamentous in Ratitae. This ligament is united at one end to the tibia, at the other to a bony projection apparently developed on the fibulare (=calcaneum) both in the Ratite and the young Carinate. It probably corresponds to the anterior annular ligament of the human foot. The distal tarsal elements are represented by a single cartilage which corresponds eventually to the second, third, and fourth metatarsalia. The rudimentary fifth metatarsal fuses with it (Baur).
The metatarsalia in Archaeopteryx are apparently free, or but slightly anchy-losed. In Penguins the three metatarsalia (ii., iii., iv.) are short and lie parallel to one another. They are not raised from the ground in them nor in Auks and Divers. Mt. iii. is the largest as a rule, but Mt. iv. is as large in some birds and much larger in Hesperornis. The calcar of the Fowl ossifies independently, but fuses with Mt. iii. Mt. i. is only anchylosed to Mt. ii. in Phaethon. All the toes are united by a common web in the embryo - a condition which persists in the Pelican, Cormorant, Solan Goose, and Divers. They rarely all retain their primitive forward position, e. g. in the Penguin, Swift, etc. The hallux is sometimes absent.
Aves, Selenka and Gadow, Bronn's Klass. und Ordn. des Thierreichs, vi. Abth. iv. Birds, W. K. Parker and A. Newton, Encyclopaedia Britannica, (ed. ix.) iii. Oiseaux fossiles de la France, etc, Milne-Edwards, 2 vols. and Atlas, Paris, 1867-71. Eappareil locomoteur des oiseaux, Alix, Paris, 1874. Palatal and other characters. Huxley, P. Z. S. 1867, 1868.
Pigeon. T. J. Parker, Zootomy, London, 1884, p. 182.
Fossil Birds. Archaeopteryx. Dames, Palaeont. Abhandl., Berlin, ii. part 3, 1884. Marsh, Nature xxv. 1881-82. Vogt, The Ibis, 1880. Owen, Ph. Tr. 153, 1863. Cf. Baur, Z. A. ix. 1886, for complete lit. Odontornithes (Hesperornis, Ichthyornis). Marsh, Memoir, United States Geological Exploration, 40th parallel, 1880. Odontopteryx. Owen, Journal Geol. Soc. xxix. .1873. Dinornis, etc. Id. Extinct Birds of New Zealand, 2 vols. 1879. -Dodo, Strickland and Melville, London, 1848. Solitaire, Newton and Clark, Ph. Tr. 168, 1878.
Skull. Development and Structure, W. K. Parker, 'Fowl,' Ph. Tr. 159, 1869, Cf. Id. Morphology of Skull, London, 1877, p. 219. Of other Birds and groups, Monthly Microscopical Journal, 1872, 1873; Tr. L. S. (2) i. 1879; Tr. Z. S. ix. 1877 j x. 1879.
Structure of Pneumatic bones. Wildermuth, J. Z. xi. 1877.
Vertebral column, etc. Articulations, Jager, SB. Wien. Akad. xxxiii. 1858. Axial skeleton. Mivart, Tr. Z. S. viii. 1874; x. 1879. Pygostyle. W. Marshall, Niederland. Archiv f. Zool. i. 1871-73, p. 194. Birds vertebrae. Marsh, American Journal of Science and Arts, xvii. 1879.
Processus uncinatus. Behrens, Inaugural Dissertation, Gottingen, 1880.
Shoulder-girdle. Hoffman, Niederland. Archiv f. Zool. v. 1879-82. Bunge, Inaugural Dissertation, Dorpat, 1880. Gegenbaur, Untersuch. zur Vergleich. Anat. der Wirbelthiere, ii. Leipzig, 1865. Sabatier, Comparaison des ceintures, Paris, 1880. Harting, L'appareil episternale des oiseaux, Naturkundigen Ver-handlungen, Utrecht, 1864. Shoulder and Elbow joint. Fiirbringer, M. J. xi. 1885.
Shoulder girdle and Sternum. Gotte, A. M. A. xiv. 1877, p. 549. W. K. Parker, Ray Society, 1868. Miss Lindsay, P. Z. S. 1885.
Sacrum and Pelvis. Gegenbaur, J. Z. vi. 1871; cf. Huxley, P. R. S. xxviii. 1879, p. 399. Pelvis of Birds and Deinosauria, Baur, M. J. x. 1885. Prae-pubisr Miss Johnson, Q. J. M. xxiii. 1883.
Carpus and carpo-metacarpus. Rosenberg, Z. W. Z. xxiii. 1883
Tarsus. Morse, Memoirs, Boston Soc. Nat. Hist. 1880. Baur, M. J. viii.' 1882. Cf. Id. op. cit. x. 1885, p. 446, and Z. A. viii. 1885. Foot in Birds. Forbes, Ibis, 1882. Rudimentary Hallux. Id. P. Z. S. 1882.
Teeth in living Birds. Fraisse, Verhandl. Phys. Med. Gesellschaft, Wurzburg, xv. 1881, SB. p. iii.
Effects of artificial selection. Darwin, Animals and Plants under Domestication, i. caps. v. vi. (ed. ii.) 1875. See also his Index.