Make a labelled diagrammatic representation of the basic forms and diversities in Echinoderm larvae and describe their evolutionary significance. (UPSC 2014, 20 Marks, )

मूलभूत रूपों और एकिनोडर्म लार्वा में विविधताओं का एक लेबलयुक्त आरेखात्मक प्रतिनिधित्व बनाएं और उनके विकासात्मक महत्व का वर्णन करें। (Make a labelled diagrammatic representation of the basic forms and diversities in Echinoderm larvae and describe their evolutionary significance.)