Annelius means"little rings" becoz they have metamerically segmented bodies .They shows bilateral symmetry. They are triplobastic(having three germ layers). They are the first true coelomates having true coelom(body cavity).Annelidsbelongs to "Kingdom Animalia" and "Phlum Annelida".They are classified into 3 main classes that is: 1. Polychaeta 2. Oligochaeta 3. Hirudinea Examples are: 1. Neries. 2. Earthworm (pheretima posthuma). 3. Leech (huridinaria medicinallis).