BIRD. 105 BIBB. Trans. Zoiil. Soc. of London (London, 1844) ; Proc. Zool. iS'oc London (London, 1878 and 1879, many articles) ; Wardlaw-Kauisay, Ibis (London, 1884 and 188G) ; Blasius, Trans. Linncean Soc. of London, and Ibis (London, 1884-88) ; and I'roc. Zool. Soc. (London, 1888, and subse- quently). Africa. — ^Layard, Birds of South Africa, 2d ed. (London, 18S4) : Andersson, Xotes on the Birds of Damara-land (London, 1872) ; Heuglin. Orni- thologie Xordostafrikas (Cassel, 1875) ; Finsch and Hartlaub, Vogel Ostafrikas (Leipzig, 1870) ; Hartlaub, System der Ornitholopie West Af- ricas (Bremen, 1857); Shelley, Handbook to the Birds of Egypt (London, 1872) : Tristram, Fauna and Flora of Palestine (London, 1884) ; Milne-Edwards and Grandidier, IJist. nai. des oiseaux de Madagascar (Paris, 1884). South and Central Ainerica. — Azara, Hi^t. tiat. de los pdjaros del Paraguay y Rio de la Plata (Madrid, 1805) ; Belt, .4. yaturalist in yicaragua (London, 1888): Bates, The Xaturalist on the .Amazon (London, 1863) ; Sclater and Salvin, Biologia Ccntrali Americana, Birds (London, ( 1880) ; Cory, Birds of the West Indies (Boston, 1889) ; Darwin, A Xaturalist's Voyage (London, 1860) ; Sclater and Hudson, Argentine Ornithol- ogy (London, 1889). See also Proceedings of the United Slates yational Muscutn, and those of the Zoological Society of London, since 1870. BIRD, Fossil. Fossil remains that could be referred to birds were among the later ac- quisitions of paleontologists. The first were mis- takenly so considered, and consisted of the famous 'bird-tracks' discovered in the 'brown- stone' rocks of the Connecticut River by Hitch- cock, about lS.'i5. and extensively studied by him. These footprints may possibly, in a few instances, be traces of primitive animals properly called birds, but so far as known all are impressions made upon mud by dinosaurs and similar am- phibians or reptiles of the Triassic Age. (See DixosAURiA; Stegocei'uajja, etc.) More re- cently true birds have been found fossil from the Jurassic Age onward, but their remains are ev- er>-vvhere comparatively scarce, due mainly to the easy destructibility of their bodies. The earliest to be identified proved to be also the earliest in time, and consisted of the remains in the .Jurassic slates of Bavaria of Arch^opteryx, whose characteristics are fully described under Abch.iopteryx. This seems to have been a true feather-clothed bird, with well-formed wings, but a long lizard-like tail, beset on each side with a row of horizontal quill-feathers, and a heron-like beak studded with teeth. These characteristics are so radically difl'erent from those of all other birds that the archa'opteryx is classified in a subclass of itself termed Arch.xornithes; all other birds, fossil and recent, forming another subclass, Xeornithes or Euornithes. A long gap in geological time separates the period of the archa>opter>-x from the next earliest fossil birds known, which belong to the upper, or more recent, part of the Cretaceous Age. These fonna- lions in Europe and India, but especially in the western United States, have yielilcd varied re- mains of large birds, which, because all have teeth in the beak, have been called Odontornithes or Odontolcae. -Ml are still of a low type of organization, showing many points of genetic affinity with reptiles, but far advanced beyond Archaeoptcryx : and all were aquatic and fish- eating. They approximate, indeed, so closely to the ordinary carinate birds of the present time that they are included with them in a single sub- class, as above noted, of which, say Parker and Haswell, "they will constitute a separate series characterized by the possession of teeth and . . . that the two halves of the lower jaw remain completely separate in front, instead of having a solid bony union. Of these toothed birds the one type is known as Ichthyornis, and comprises somewhat gull-like birds characterized by having a numerous series of teeth implanted in distinct sockets, and also by the vertebrae or joints of the back articulating with one another by means of cup-like surfaces (instead of sad- dle-shaped). ... It is quite within the bounds of possibility that these birds may be ancestral types of the modern gulls. With Uesperornis (q.v.) we are confronted with a totally different type, in which the teeth were im- ])lanted in an open groove, while the wings were rudimentary and the keel of the breast-bone was wanting, although the vertebrae resembled those of existing birds. In general organization, Hes- perornis, indeed, approximated very closely to the modern divers. . . . That it was thoroughly aquatic in its habits is self-evident; while it may . . . be regarded as a specialized and flight- less offshoot from the ancestral stock of the modern divers." The discovery and elucidation of these Cretaceous toothed birds was made chiefly by Prof. 0. C. Marsh, of Yale L'niversity, between 1870 and 1880, and his novelties in- cluded a large number of skeletons or fragments which have been referred to various genera and are preserved in the Yale iluseum at N'ew Haven. "They afford a most valuable contribution in favor of the doctrine of evolution, approximating more and more, as we descend in the geological scale, to reptiles, from which it may be confi- dently stated the avian class has originated." With the closing of the Cretaceous Period, toothed birds seem to have disappeared, for bird-fossils from the early formation of Tertiary age lack them, and in general approach closely to modern types. Few of these fossils have been found in Xorth America, but Europe and South America have supplied many genera and species of various groups, increasing in numbers as we rise in the geologic scale. Among the oldest (Eocene) were certain gigantic forms, character- ized by long, powerful legs and small and appar- ently useless wings, but especially by "the enor- mous and ponderous structure of tlie skull, which is quite unlike that of any recent bird, and seems out of all proportion to the limbs, gigantic as are some of the leg-bones." These have been com- bined into a group (Stereornithes) including many species, chiefly of the genera Brontornis and Phororhacos, from the Miocene of Patagonia. "Brontornis, for example." according to Lucas, '"had leg-bones larger than those of an ox: . . . while the great Phororhacos, one of his contemporaries, was not only nearly as large, but qiiite uni(|ne in build. Imagine a bird seven or eight feet in height, from tlip sole of his big, sharp-clawed feet to the top of his huge head, poise this head on a neck as thick as that of a horse, arm it with a beak as sharp as an ice- pick and almost as formidable, and you have a fair idea of this feathered giant of the ancient pampas." The skull e(|ualed in size that of ii large horse, but whether this great equipment
