Philinorbis Habe 1950

Genus Philinorbis Habe, 1950

Philinorbis Habe, 1950: 52. Type species (by monotypy): Philinorbis teramachii Habe, 1950. Japan.

? Pseudophiline Habe, 1976: 154. Type species (by original designation): Pseudophiline hayashii Habe, 1976. Japan.

Diagnosis. Shell internal, rounded, with lip extending well above apex; sculpture smooth or with spiral lines. Live animals with cephalic shield broad and rhomboid; pallial lobe elongate, lacking posterior notch; gizzard nonmuscular, with reduced brown chitinous gizzard plates, sometimes absent; radula with short, broad, and hookshaped inner lateral teeth, smooth or with fine denticulation along inner edge; penial atrium embedded in tissue anteriorly to body cavity.

Remarks. According to Oskars et al. (2015) members of Philinorbidae are genetically distinct from Philinidae. The anatomy of Philinorbidae suggests a close relationship with the northeastern Pacific species Philine alba Mattox, 1958, and consequently is here included in Philinorbidae. Only one valid genus, Philinorbis is currently included in this family, which is represented in the northeastern Pacific by a single species.

Chaban (2011) considered Pseudophiline as a synonym of Philinorbis. This opinion was later substantiated by Oskars et al. (2015), who indicated that members of these two genera share the presence of the diagnostic family traits listed above. More recently, Chaban (2016) reversed her opinion, based on anatomical differences between species recently described from the Philippines by Gozales & Gosliner (2014), and considered Pseudophiline to be distinct from Philinorbis. Because of limited information on the type species of these two genera and the lack of comprehensive phylogenies for this group we provisionally and tentatively regard Pseudophiline and Philinorbis as synonyms.