line spectrum: a spectrum in which energy is concentrated at particular wavelengths; produced by excited atoms and ions as they fall back to a lower energy level
spectrum: an ordered array of the components of an emission or wave
superclass myriapoda: used in some classifications to encompass the millipedes (Diplopoda) and centipedes (Chilopoda); formerly a large taxon including also the Pauropoda and Symphyla; the term Myriapoda now usually used synonymously with Diplopoda and limited to the millipedes