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 equator is located at zero degrees latitude. The equator runs through Indonesia, Ecuador, northern Brazil, the Democratic Republic of the Congo, and Kenya, among other countries.he equator divides the planet into the Northern and Southern Hemispheres. On the equator, the length of day and night are equal every day of the year-day is always twelve hours long and night is always twelve hours long. The Tropic of Cancer and the Tropic of Capricorn each lie at 23.5 degrees latitude.