Abstract
The embryology of Anthopleura elegantissima and Anthopleura xanthogrammica is described. Ova of A. elegantissima are 120–150 μm in diameter and brown, while those of A. xanthogrammica are 175–225 μm in diameter and purple. In both species, cleavage is complete and equal: endoderm formation is by emboly. The planulae of both species are similar in appearance and are 150–250 μm in length with an apical tuft 60–75 μm in length. Feeding of the planulae is discussed, as is the function and phylogenetic significance of the apical sensory tuft of the planula.