Apparently endemic to South Africa.
Volvatella laguncula is illustrated in Terry Gosliner's book on Sth African opisthobranchs. It was originally named on the basis of two empty shells, but Tom Thompson (1979) studied living animals and reported that it fed on the 'roots' of the green alga Caulerpa filiformis. Identifying species of Volvatella is difficult because we do not really know much about the geographic distribution and shell variability of any of the described species. On existing information, this species seems to be endemic to southern Africa.
The animal and shell are translucent white.
Thompson, T. E. (1979) Biology and relationships of the South African sacoglossan mollusc Volvatella laguncula. Journal of Zoology, London 189: 339-347, Figs 1,2a-d.
Rudman, W.B., 2008 (June 2) Vovatella laguncula Sowerby, 1894. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/volvlagu