Note
This paper reports a comparative study of the gross structure, histology, and functional morphology of several pelagosphera larvae, both lecithotrophic and planktotrophic, representing 6 species of sipunculans. Of the larvae described, 3 were reared from eggs of the following tropical and subtropical species: Themiste alutacea, Golfingia pellucida, and Phascolosoma perlucens; others were collected from plankton tows in the Florida Current and specific adult affinities are uncertain.