There are no previous ultrastructural studies of a photoreceptoral organ in representatives of the phylum Entoprocta. It has been reported, however, that larvae of some species possess eyespots and that larvae of certain species exhibit phototactic behavior. The larval eyespots of an unidentified member of the family Loxosomatidae were examined by light and electron microscopy to aid in clarifying the potential light-sensitive nature of these structures. The larval eyespots present the following attributes of photoreceptoral organs: a sensory cell with extensive membranous surface formed, in this instance, by numerous modified cilia—the presumed photoreceptor—which have a 9× 2 + 2 axoneme but no arms on the a-microtubules and which are oriented with their long axes perpendicular to the direction of incident illumination; a cup-shaped, subepidermal pigmented cell which provides for directional illumination of the cilia; and a lens cell through which light passes before reaching the suggested receptoral organelles. Comparisons are made between features of the eyespot of the loxosomatid larva and those of previously described photoreceptoral organs in representatives of other phyla.