Nautilus macromphalus

The nautilus is a pelagic marine mollusc of the cephalopod family Nautilidae. The nautilus is the sole extant family of the superfamily Nautilaceae and of its smaller but near equal suborder, Nautilina.

New Caledonia is a sui generis collectivity of overseas France in the southwest Pacific Ocean, south of Vanuatu, about 1,210 km (750 mi) east of Australia, and 17,000 km (11,000 mi) from Metropolitan France. The archipelago, part of the Melanesia subregion, includes the main island of Grande Terre, the Loyalty Islands, the Chesterfield Islands, the Belep archipelago, the Isle of Pines, and a few remote islets. The Chesterfield Islands are in the Coral Sea. French people, especially locals, call Grande Terre "Le Caillou".

Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of 7,617,930 square kilometres (2,941,300 sq mi), Australia is the largest country by area in Oceania and the world's sixth-largest country. Australia is the oldest, flattest, and driest inhabited continent, with the least fertile soils. It is a megadiverse country, and its size gives it a wide variety of landscapes and climates, with deserts in the centre, tropical rainforests in the north-east, and mountain ranges in the south-east.

A callus is an anatomical feature that exists in some mollusk shells, a thickened area of shell material that can partly or completely cover the umbilicus, or can be located as a coating on the body whorl near the aperture of the shell.

The umbilicus of a shell is the axially aligned, hollow cone-shaped space within the whorls of a coiled mollusc shell. The term umbilicus is often used in descriptions of gastropod shells, i.e. it is a feature present on the ventral side of many snail shells, including some species of sea snails, land snails, and freshwater snails.

In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work mainly like muscular hydrostats. Most forms of tentacles are used for grasping and feeding. Many are sensory organs, variously receptive to touch, vision, or to the smell or taste of particular foods or threats. Examples of such tentacles are the eyestalks of various kinds of snails. Some kinds of tentacles have both sensory and manipulatory functions.

A cenote is a natural pit, or sinkhole, resulting from the collapse of limestone bedrock that exposes groundwater. The regional term is specifically associated with the Yucatán Peninsula of Mexico, where cenotes were commonly used for water supplies by the ancient Maya, and occasionally for sacrificial offerings. The term derives from a word used by the lowland Yucatec Maya—tsʼonoʼot—to refer to any location with accessible groundwater.

Lifou [lifu] is a commune of France in the Loyalty Islands Province of New Caledonia in the Pacific Ocean.

Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant rocks, such as quartzite, given the right conditions. Subterranean drainage may limit surface water, with few to no rivers or lakes. However, in regions where the dissolved bedrock is covered or confined by one or more superimposed non-soluble rock strata, distinctive karst features may occur only at subsurface levels and can be totally missing above ground.

The Gazelle Peninsula is a large peninsula in northeastern East New Britain, Papua New Guinea located on the island of New Britain within the Bismarck Archipelago, situated in the southwestern Pacific Ocean. The Rabaul caldera is located on the northern tip of the peninsula. Upon the Gazelle Peninsula are the Baining Mountains, of which the highest point is Mount Sinewit at 2,063 m (6,768 ft). The Gazelle Peninsula houses Vulcan Crater and Mount Tavurvur, both of which conducted volcanic activity in the 20th and 21st centuries and have provided extremely fertile soils. The body of the Gazelle Peninsula is about 80 km (50 mi). The southern isthmus upon which the Gazelle Peninsula is connected to the main body of East New Britain is reduced to about 32 km (20 mi).