No species in this clade have shells as adults.[2][3] These slugs are distinguished by the location of the anus at the rear of the body.[4]
Although neither superfamily bears shells as adults,[3] the Onchidioidea do possess a vestigial, non-mineralized shell sac[5] and possess a larval shell.[6] It is not known whether or not the veronicellids bear a larval shell.[7]
^ abSchilthuizen M.; Thome J. W. (2008). "Valiguna flava (Heynemann, 1885) from Indonesia and Malaysia: Redescription and Comparison with Valiguna siamensis (Martens, 1867) (Gastropoda: Soleolifera: Veronicellidae)". Veliger. 50 (3): 163–170.
^Barnes, Robert D. (1982). Invertebrate Zoology. Philadelphia, PA: Holt-Saunders International. p. 377. ISBN0-03-056747-5.
^TILLIER, S (1983). "A new mountain Platevindex from Philippine Islands (Pulmonata: Onchidiidae)". Journal of Molluscan Studies. 49 (supp12A). Malacological Soc London: 198.