Belongs within: Euopisthobranchia. Bulla is a genus of relatively large bubble snails with a well-developed shell into which the animal is able to withdraw completely. Shells of the various species are largely very similar in appearance, leading to taxonomic confusion in the genus. Characters (from Malaquias & Reid 2008): Shell ovoid, solid, mottled in drab… Continue reading Bulla


Belongs within: Heterobranchia.Contains: Aplysiidae, Akeridae, Gymnosomata, Thecosomata, Runcinidae, Umbraculidae, Cylichnidae, Diaphanidae, Retusidae, Rhizoridae, Acteocina, Tornatina, Bulla, Atys, Haminoea, Philinidae, Aglajidae, Philinoglossidae, Scaphandridae. The Euopisthobranchia are a major clade of marine gastropods supported by molecular data, including the bubble shells, sea hares and pteropods. Subgroups include the Aplysiida, sea hares and related taxa, a group of soft-bodied marine… Continue reading Euopisthobranchia


Belongs within: Euopisthobranchia. The Aglajidae are a cosmopolitan group of headshield slugs in which the shell is internal, reduced and often not calcified, and the visceral shield is posteriorly extended into swallowtail-like lobes. <==Aglajidae [Sinistrobranchia, Sinistrobranchidae]BR17 |–PosterobranchaeaBR05 |–Doridium Meckel 1809 [Doridiidae, Doridiina, Doridiinae]BR05 | `–*D. membranaceum Meckel 1809BR17 [=Aglaja membranaceaO27] |–Navanax Pilsbry 1895O27 | `–*N.… Continue reading Aglajidae


Belongs within: Euopisthobranchia. The Diaphanidae are a group of thin-shelled bubble snails lacking mantle parapodia, jaws or gizzard plates. The shell is transparent in life, less than five millimetres long, and has a truncate spire. <==DiaphanidaeBR05 |–BogasoniaJ96 |–RhinodiaphanaJ96 |–Brocktonia Iredale 1915O27 | `–B. polystrigma Dall 1908O27 |–Austrodiaphana Pilsbry 1896P61, BR05 [Austrodiaphanidae] | |–*A. brazieri (Angas… Continue reading Diaphanidae


Belongs within: Euopisthobranchia. The Retusidae, canoe shells, are a family of infaunal cephalaspid gastropods characterised by the lack of a radula. Instead, their diet of forams and minute molluscs is processed by gizzard plates. <==Retusidae [Retusacea, Retusoidea] |–Ventomnestia girardi (Audouin 1827) [=Bulla girardi, Alicula girardi, Cylichna girardi]BD86 `–Retusa Brown 1827 [Crypsibranchia]BR05 | i. s.: R.… Continue reading Retusidae


Belongs within: Euopisthobranchia.Contains: Cavoliniidae. The Thecosomata, sea butterflies, are a group of pelagic marine gastropods that have the foot modified into a pair of wing-like parapodia used in swimming. Most Thecosomata retain a calcareous shell though the shell is demineralised or lost in some subgroups. Loss of the adult shell is found in the Cymbuliidae… Continue reading Thecosomata


Belongs within: Euopisthobranchia. The Philinidae are a group of headshield slugs with a delicate internal shell and a dorsal aspect divided between the four regions of head, visceral mass and lateral parapodial lobes. They commonly live infaunally in fine sediments; a smaller number of species live epifaunally. <==PhilinidaeBR05 |–Megistostoma gabbianum (Stoliczka 1868)TTE93 |–Bullaea Lamarck 1801… Continue reading Philinidae


Belongs within: Euopisthobranchia. The Gymnosomata are a group of shell-less, pelagic marine gastropods in which the foot has been modified into a pair of large parapodia used for swimming. The lateral position of the parapodia well behind the head has lead to their vernacular name of ‘sea angels’. <==Gymnosomata |–Hydromyloidea [Gymnoptera, Laginiopsina]BR05 | |–Laginiopsis Pruvot-Fol… Continue reading Gymnosomata


Belongs within: Thecosomata.Contains: Cavoliniinae. The Cavoliniidae are a group of sea butterflies with a straight, uncoiled shell present at maturity. The shell is conical in Styliola and Hyalocyclis but dorsoventrally depressed in Cuvierina and Cavoliniinae. Members of the Cavoliniinae also bear lateral ridges on the shell (Corse et al. 2013). <==Cavoliniidae (see below for synonymy)… Continue reading Cavoliniidae


Belongs within: Cylichnidae. Cylichna, the chalice bubble snails, is a genus of marine gastropods characterised by a cylindrical shell with a long aperture and simple columella. In life, the shell mostly sits behind the visible body which is covered by the large head shield. Cylichna Lovén 1846BR05 |–*C. cylindracea (Pennant 1777)BR17 [=Bulla cylindraceaBR17; incl. C.… Continue reading Cylichna