1888 G. Rolleston & W. H. JacksonForms Animal Life (ed. 2) 546 In Echnoidea..the pore shifts either actinally (to the left) or abactinally (to the right).
1972 Jrnl. Royal Soc. N.Z.2 147 No pedicellariae present, either abactinally, marginally or actinally.