Choristella

Herbert, David G., 2015, An annotated catalogue and bibliography of the taxonomy, synonymy and distribution of the Recent Vetigastropoda of South Africa (Mollusca), Zootaxa 4049 (1), pp. 1-98 : 9

Choristella sp.—new record

Distribution. A single empty, somewhat damaged shell has been dredged on the Agulhas Bank (off Cape St Francis, E. Cape), 210 m.

Notes. The fragile, smooth, globose, white shell, with a deeply channelled suture and distinct umbilical carina indicate that this material is referable to Choristella . The specimen also resembles Trenchia agulhasae ( Clarke, 1961) [ Seguenzioidea incertae sedis ( McLean 1992; Kano et al. 2009)], but that species occurs at abyssal depths and is smaller than the present specimen (diameter 3.0 mm vs. 4.5 mm). It also has a basal carina in addition to the umbilical carina. The poor quality of the specimen does not permit more in-depth evaluation, but I mention it to draw attention to the probable occurrence of Choristella in South African waters. Living specimens are to be sought inside spent egg cases of elasmobranch fish, where they feed on the inner layers of the capsule.