M. E.  Rice, ?Sipuncula?, in Microscopic Anatomy of Invertebrates: Onychophora, Chilopoda, and lesser Protostomata, New York: Wiley-Liss, 1993, pp. 237-325.

M. E.  Rice, ?Two new species of Phascolion (Sipuncula: Phascolionidae) from tropical and subtropical of the central western Atlantic?, Proceedings of the Biological Society of Washington, vol. 106, pp. 591-601, 1993.