Of the geological antiquity of the Columbæ we have no evidence; but their wide distribution, their varied forms, and their great isolation, all point to an origin, at least as far back as that we have assigned as probable in the case of the Parrots.

Order V.—GALLINÆ.

Family 86.—PTEROCLIDÆ. (2 Genera, 16 Species.)

General Distribution.
Neotropical
Sub-regions.		Nearctic
Sub-regions.		Palæarctic
Sub-regions.		Ethiopian
Sub-regions.		Oriental
Sub-regions.		Australian
Sub-regions.
— — — —— — — —— 2. 3. 41 — 3. 41 — — —— — — —

The Pteroclidæ, or Sand-grouse, are elegantly formed birds with pointed tails, and plumage of beautifully varied protective tints, characteristic of the Ethiopian region and Central Asia, though extending into Southern Europe and Hindostan. Being pre-eminently desert-birds, they avoid the forest-districts of all these countries, but abound in the most arid situations and on the most open and barren plains. The distribution of the genera is as follows:—

Pterocles (14 sp.), has the same range as the family; Syrrhaptes (2 sp.), normally inhabits Tartary, Thibet, and Mongolia to the country around Pekin, and occasionally visits Eastern Europe. But a few years back (1863) great numbers suddenly appeared in Europe and extended westward to the shores of the Atlantic, while some even reached Ireland and the Færoes. (Plate III. Vol. I. p. 226.)

Family 87.—TETRAONIDÆ. (29 Genera, 170 Species.)

General Distribution.
Neotropical
Sub-regions.		Nearctic
Sub-regions.		Palæarctic
Sub-regions.		Ethiopian
Sub-regions.		Oriental
Sub-regions.		Australian
Sub-regions.
— 2. 3. 41. 2. 3. 41. 2. 3. 41. 2. 3. 41. 2. 3. 41. 2 — 4.

The Tetraonidæ, including the Grouse, Partridges, Quails, and allied forms, abound in all parts of the Eastern continents; they are less plentiful in North America and comparatively scarce in South America, more than half the Neotropical species being found north of Panama; and in the Australian region there are only a few of small size. The Ethiopian region probably contains most species; next comes the Oriental—India proper from the Himalayas to Ceylon having twenty; while the Australian region, with 15 species, is the poorest. These facts render it probable that the Tetraonidæ are essentially denizens of the great northern continents, and that their entrance into South America, Australia, and even South Africa, is, comparatively speaking, recent. They have developed into forms equally suited to the tropical plains and the arctic regions, some of them being among the few denizens of the extreme north, as well as of the highest alpine snows. The genera are somewhat unsettled, and there is even some uncertainty as to the limits between this family and the next; but the following are those now generally admitted:—

Ptilopachus (1 sp.), West Africa; Francolinus (34 sp.), all Africa, South Europe, India to Ceylon, and South China; Ortygornis (3 sp.), Himalayas to Ceylon, Sumatra, and Borneo; Peliperdix (1 sp.), West Africa; Perdix (3 sp.), the whole Continental Palæarctic region; Margaroperdix (1 sp.), Madagascar; Oreoperdix (1 sp.), Formosa; Arborophila (8 sp.), the Oriental Continent and the Philippines; Peloperdix (4 sp.), Tenasserim and Malaya; Coturnix (21 sp.), Temperate Palæarctic, Ethiopian and Oriental regions, and the Australian to New Zealand; Rollulus (2 sp.), Siam to Sumatra, Borneo, and Philippines; Caloperdix (1 sp.), Malacca and Sumatra; Odontophorus (17 sp.), Brazil and Peru to Mexico; Dendrortyx (3 sp.), Guatemala and Mexico; Cyrtonyx (3 sp.), Guatemala to New Mexico; Ortyx (8 sp.), Honduras and Cuba to Canada; Eupsychortyx (6 sp.), Brazil and Ecuador to Mexico; Callipepla (3 sp.), Mexico to California; Lophortyx (2 sp.), Arizona and California; Oreortyx (1 sp.), California and Oregon (Plate XVIII., Vol. II. p. [128]); Lerwa (1 sp.), Snowy Himalayas and East Thibet; Caccabis (10 sp.), Palæarctic region to Abyssinia, Arabia and the Punjaub; Tetraogallus (4 sp.), Caucasus and Himalayas to Altai Mountains; Tetrao (7 sp.), northern parts of Palæarctic and Nearctic regions; Centrocercus (1 sp.), Rocky Mountains; Pediocætes (2 sp.), North and North-west America (Plate XVIII. Vol. II. p. [128]); Cupidonia (1 sp.), East and North-Central United States and Canada; Bonasa (3 sp.), north of Nearctic and Palæarctic regions; Lagopus (6 sp.), Arctic Zone and northern parts of Nearctic and Palæarctic regions.