1. Wilson, D. P., in Perspectives in Marine Biology, edit. by Buzzati-Traverso, A. A., 87 (University of California Press, Berkeley, and Los Angeles, 1960).
2. Armstrong, F. A. J., J. Mar. Biol. Assoc. U.K., 31, 335 (1952); ibid., 33, 347 (1954); ibid., 37, 331 (1958); ibid., 41, 663 (1961).
3. Lucas, C. E., Biol. Rev., 22, 270 (1947).
4. Lucas, C. E., Symposia Soc. Exp. Biol., 3, 336 (1949).
5. Lucas, C. E., Deep Sea Res., 3, Suppl., 139 (1955).