so·mite 
(sōmīt′)
(sōmīt′)n.
1. Any of the homologous segments that compose the body of certain animals, such as earthworms and lobsters, and are arranged in a longitudinal series.
2. A segmental mass of mesoderm in the vertebrate embryo, occurring in pairs along the notochord and developing into muscles and vertebrae.
[Greek sōma, body; see SOMA1 + -ITE1.]
so·mitic (sō-mĭtĭk) adj.