The Oligocene period is represented by a succession of layers principally of marine origin, which appear in the province of Entre Rios along the whole length of the Parana River. The same layers reappear farther south at the mouth of the river Negro and extend along the Patagonian coast as far as the Gulf of Nuevo.
Remains of the Miocene period cover the central and southwestern Pampas, as well as a portion of Catamarca and Tucuman. To this period belongs the inunense quantity of rounded gravel which covers the whole surface of Pata gonia from the river Negro to the south. .
Of the Pliocene period may be found rep resentations in the Pampean formation, or in the great deposit of lime and reddish gray clay which covers the province of Buenos Aires.
Representations of the Quaternary and re cent epochs are met with in isolated deposits throughout the length of the republic.
Flora.— According to Professors Holm berg, Spegazzini, and Gallardo, the Argentine flora represents almost one-tenth of the flora of the world. Professor Stuckert claims to have studied and classified as many as 8,000 phanerogamous • and vascular cryptogamous plants. The number of known plants among the cryptogamous alone is calculated at 3,000 species. Only a fourth of the phanerogamous and less than a tenth of the cryptogamous plants have been classified. The microscopic flora is almost entirely unknown. The prov ince of Buenos Aires is almost devoid of trees; the only part where they are found is along the coast, but they are small and consist prin cipally of mimosa, which make excellent fuel. Calden is to be found in the west. In part of Santa Fe, the Chaco, Santiago del Estero, Entre Rios, Corrientes, Misiones, Tacuman, etc., there are immense forests of the finest and most useful classes of trees, from the easily woiked cedar to the qucbraco (axe breaker) used for railway sleepers, fiandubay for fenc ing posts, lapacho, algarroba and numerous varieties of wood for shipbuilding and fur nittire. The omba is useless as timber, and is not even suitable for firewood, but is valued for its shade, while the ceibo bears an extremely beautiful flower of a deep crimson color.
Fauna.— Very few species of animals per tain exclusively to Argentina. Among the mammals are recognized two, the vizcacha, which is not found outside of the Pampas, and the hare of Patagonia. Among birds may be numbered two species characteristic of Argen tina; the marineta, a bird of the heron family, and the gallito, or small cock, which also live on the Pampas, but farther south than the two species first named. Most of the animal species which live in Argentina are met beyond the frontiers of the country in Brazil, in Bolivia and in Chile. Some of these are also common to the Antilles and to North America.
There is a great variety and diversity in the fauna, according to the region studied, since the animals of the east or of the north differ considerably from those of the west and the south.' Dr. Lahille has divided southern South America into three regions: (1) The Andean, which comprises the whole of Chile, all of Pat agonia and the greater part of • the Andean provinces; (2) the central region, formed by the basin of the Parana River; (3) the Brazil ian, which comprises the territories of Mis iones, a part of the province of Corrientes, and also the northern part of the republic of Uru guay. In the eastern zone of Argentina live
the animals that have emigrated from the table lands of Brazil.
The wild •animals are numerous, being the jaguar (tigar), puma (leon) and various kinds of wild cats, the aguara-guazu (fox of Para guay), an animal of a reddish color with a black stripe along the back; gray and red foxes, various kinds of weasels, otters, skunks or pole cats, nutria, a rodent which is called an otter but is Myopatarnis Copyus, having a tail like a rat; seals, opossums, raccoons, vicuña, huanaco, elamas and alpacas, the last two said to be the domesticated varieties of the preced ing two, various kinds of deer varying in size from that of the red deer of Europe down to 18 inches in height; armadillos of four varie ties, the wild guinea pig, the pampa hare, which is not a hare but Dolichotis Patagonica, and several monkeys, carpincho or water hog, viz cacha or prairie dog, tapir, peccari, ant-eaters. The vizcacha was some years ago very numer ous, but is not now to be found on the inside camps, that is land that has been stocked for many years, as a war of extermination was waged against them some 25 or 30 years back. Birds are also numerous, the more notable be ing the vultures, hawks, ostrich (rhea or fiandu), eagles, owls, parrots, woodpeckers, ovenbuilders, humming birds, ibis, flamingo, spoonbill, swallows, pigeons, doves, egrets, storks, wood turkeys, partridges of various kinds, snipe, plovers, ducks, swan, geese, gulls, bustard and in the far south the penguin and other sea birds. The house sparrow was in troduced some years ago and has now become a thorough nuisance, as are also the descend ants of imported hares in Santa Fe and the north of Buenos Aires.
The best fish are the pejerrey (a kind of trout), dorado (something like salmon but of a golden color), corvina, palometa, anchoa (a large fish not a bit like an anchovy), flatfish, zurubi, an immense yellow and black spotted catfish. The only fish we know that will take the artificial fly are the pejerrey, do rado and the mojarra, a small fish very like a sardine. Alligators are still to be found in the upper Parana and Paraguay; iguanas are to be found in the northern provinces and lizards throughout the country.
Snakes are numerous but the only danger ous ones are the rattlesnake and the vibora de la cruz; possibly some of the large water boas may be so, but no instance has been reported of man being attacked by them.
Some years ago it was successfully dem onstrated that oysters could be brought from the favored localities of the United States and placed in the bays of the Atlantic coast of this republic and there multipl3r, grow and fatten.
Bibliography.-Holland, W. J., 'To the River Plate and Back: the Narrative of a Scientific Mission to South America' (New York 1913) ; Mills, J. G., 'Argentine: Physical Features,' etc. (New York 1914) ; Pan-Ameri can Union, 'Argentine Republic: General De scriptive Data' (Washington 1914); Ross G., 'Argentina and Uruguay' (New York 1916) ; Willis, B., 'Northern Patagonia, Character and Resources> (Vol. I, a study of the elements of development in the region tributary to the national railway from Port San Antonio to Lago Nahuel Huapi, etc, under caption Min istry of Public Works, Buenos Aires 1911-14). See also Bibliographies under HISTORY, AGRI CULTURE, etc.