North of the mountain region of Venezuela lies what may be considered as the coastal plain, including the alluvial area of the Lake of Maracaibo, the Coro and Paraguana lowlands, and such few tracts of flat ground as may be found along the coast, with the numerous islands in the Caribbean which belong to Venezuela. The area of this division may be estimated as about 27,800 square miles. The lake has many points of similarity to the Delta, both in hydrography and general character. The southern part has innumerable rivers comparable to the caños, with open lagoons and swamps, bordered by dense forests more or less inundated in the rains. On the east and west shores to the north there are stretches of higher ground between the swamps, and frequent grass plains like the Llanos; the western side is bounded by the Sierra de Perija, forming the frontier of Colombia. Chief of the rivers traversing these plains are the Motatán and Chama, already mentioned as rising in the Andes, the Escalante, and the Catatumbo; the mouths of all are of a deltaic character, and all are navigable to a greater or lesser extent. The largest and most important is the Catatumbo, which, with its great tributary, the Zulia, rises in Colombia. The Coro and Paraguana lowlands form a stretch of open, sandy, more or less barren and low hills, extending from the neighbourhood of the port of Maracaibo along the coast to Coro, and into the Paraguana peninsula; with them may be grouped the islands, which are similar in character, except Margarita, whose mountains resemble those of the Caribbean chain, though the open, cactus-covered lower ground is a repetition of the western coast (and Curaçao). The climate of the 394,000 square miles naturally varies greatly according to latitude, elevation, and vegetation. The Guayana region, here also, stands by itself, both from its southern position and comparatively uniform elevation, so that over a wide area the temperature and rainfall are more or less the same. Naturally in those parts of Guayana where mountain ridges rise above the general level of the plateau the temperature is lower than the average, but these must constitute a small part of the whole. There is a marked difference in the meteorological conditions in the various river-valleys of the Orinoco basin, where the “white-water”—_i.e._, the swiftly flowing but muddy streams, with rocky beds—are always accompanied by a clear sky overhead, and mosquitoes and crocodiles abound; on the “black water”—the deep and slow rivers—the sky is continually clouded, but the air is free from mosquitoes. The Orinoco represents the former type, the Rio Negro the latter. The rainy season in Guayana begins in April and lasts till November; the remaining four months are fairly dry.