The body wall of cnidarians consists of an outer layer or epidermis, an inner layer or gastrodermis, and a middle layer or mesoglea. Cnidarians lack organs and posses a primitive nervous system known as a neural net. Cnidarians exhibit two basic structural forms, a medusa and a polyp. The medusa form is a free-swimming structure which consists of an umbrella-shaped body (called a bell), a fringe of tentacles that hang from the edge of the bell, a mouth opening located on the underside of the bell, and a gastrovascular cavity.
Tropic of Capricorn, parallel of latitude at 23Â°30â south of the equator; it is the southern boundary of the tropics.This parallel marks the farthest point south at which the sun can be seen directly overhead at noon; south of the parallel the sun appears less than 90Â° from the northern horizon at any day of the year.ropic of Capricorn, parallel of latitude at 23Â°30â south of the equator; it is the southern boundary of the tropics.
The reason for the location of the Tropic of Cancer and the Tropic of Capricorn at 23.5Â° north and south respectively is due to the axial tilt of the Earth. The Earth is titled 23.5 degrees from the plane of the Earth's revolution around the sun each year.The area bounded by the Tropic of Cancer on the north and Tropic of Capricorn on the south is known as the tropics.. This area does not experience seasons because the sun is always high in the sky.he Earth is titled 23.5 degrees from the plane of the Earth's revolution around the sun each year. The area bounded by the Tropic of Cancer on the north and Tropic of Capricorn on the south is known as the tropics.. This area does not experience seasons because the sun is always high in the sky.