to permit maintenance of temperature and humidity levels different from the ambient environment. Terraria are further subcategorized by biome (tropical/temperate desert, rainforest, grassland, etc.). A terrarium may feature a horizontal land surface, an escarpment (steep slope or cliff), or a fossorial (underground) section. A Wardian case is a 19th-century sealed terrarium used for transport or display of plants or small animals such as moths under conditions where ventilation was more harmful than beneficial such as where ambient conditions were too saline, dry or polluted to support delicate species. A bottle garden is a small sealed glazed terrarium, a literal glass bottle or otherwise, in which all water and nutrients that will be required for future growth of the plant(s) and soil microorganisms are sealed into the vessel at the time of planting, the only required care being management of light and temperature. A sandwich-style terrarium is a terrarium or a section of a terrarium where soil, other firm substrate or a tree cookie (cross-section or disc) is enclosed in a narrow space between two sheets of glass or two nested jars, for observation of fossorial or woodboring animals such as earthworms, ants or termites. A glirarium (glires = dormouse) is an enclosure for housing trapped edible dormice as they fatten in preparation for hibernation. A semi-aquatic vivarium is an enclosure for species that live partially submerged or alternate between immersion in water and air. A paludarium (palus = marsh or swamp) is a semi-aquatic enclosure with aerial space above and water below, designed to house semi-aquatic plants that are rooted underwater but whose crowns reach above the surface of the water, or animals that do the same such as the mata mata. In addition to semi-aquatic plants, a paludarium may house animals such as shallow-water fish and treefrogs. The land area of a paludarium is absent or insignificant, but the term paludarium is often misused to refer to a riparium. A riparium (ripa = bank or shore) is a semi-aquatic enclosure with a land area beside a water area. Though often used for semi-aquatic animals such as newts or turtles that alternate between time in the water and on land, a riparium can simply be an aquarium-terrarium combination set together for visual effect or to use the water area as means to help increase the humidity for terrestrial species. An oceanarium is a semi-aquatic marine (saltwater) habitat, with aerial space