RELATION TO ONTOGENY AND PHYLOGENY IN ASTEROID, WITH PATICULAR REFERENCE OF THE MOST LIVING PRIMITIVE GENUS, LUIDIA

(2) This study shows the ontogeny of the present species may be correlated to the phylogenetic relationships of the species of Luidia in the following features. 1.Development of the present species is the non-brachiolarian types as all species of this genus previously reported. 2. The present observations comfirm Mortensen's view (1938) on the parallelism between the form of the bipinnaria, and the systematic position in the genus. Because bipinnaria of the present species belonging to the 2ndly advanced Alternata group (Doderlein 1920) has less one pair of bipinnaria arms than those of L. quinaria, which is included to the 3rdly advanced Quinaria group. 3. Because of just metamorphosed juvenile bearing 9 arms like the adults, the time of arms formation in multiarmed species of asteroid is related to the systematics of Luidia species.