Sabatia, Bellardi, 1876

Valdés, Ángel, 2008, Deep-sea “ cephalaspidean ” heterobranchs (Gastropoda) from the tropical southwest Pacific, Mémoires du Muséum national d'Histoire naturelle 196, pp. 587-792 : 681-682

Genus SABATIA Bellardi, 1876

Sabatia Bellardi, 1876: 209 . Type species: Sabatia isselii Bellardi, 1876 [Pliocene, Italy], by monotypy.

Synonym:

Sabatina Dall, 1908: 240 . Type species: Scaphander planeticus Dall, 1908 [Recent, Indo-Pacific], by original designation. DIAGNOSIS. — Shell morphology. Shell external, solid, oval, with only 1 whorl visible. Aperture longitudinal, as long as the shell, anteriorly rounded. Columella thickened, with a large callus composed of numerous tubercles. Operculum absent.

Anatomy. External morphology unknown. Digestive system normally with 3 irregular gizzard plates. Radula with a single hamate lateral tooth. Rachidian teeth absent. Reproductive system monaulic, with a short prostate. Penis unarmed.

REMARKS. — Bellardi (1876) introduced the genus Sabatia for a small Pliocene species of Cylichnidae having a strong parietal callus, collected in the Piedmont, Italy. Subsequently, Dall (1882) used this name for Atys bathymophila Dall, 1881 , a deep water species collected from several localities in the western Atlantic, in 1010-1610 m, and Bulla grandis Seguenza, 1880 , another fossil species from the Calabrian Pliocene, Italy. He also considered that Scaphander niveus Watson, 1883 and Scaphander gracilis Watson, 1883 probably belonged to the same group. None of these species mentioned by Dall (1882) has a parietal callus.

Dall (1890) described Bucconia as a subgenus of Scaphander , type species Scaphander nobilis Verrill, 1884 , for species of Cylichnidae having a wing raised above the apex and a globose rather than pyriform shape. The type species of Bucconia does not have a parietal callus. Later, Dall (1908) introduced the new subgenus Sabatina , for species of Cylichnidae with a callus and a globose rather than pyriform, shell.

Habe (1952a, 1955) and Kuroda & Habe (1954) used the name Bucconia for species of Cylichnidae with or without a parietal callus, and Sabatia for smaller species with a distinctive callus. In contrast, Bullis (1956) used Bucconia for species with no callus and an oval shaped shell with a wing rising above the apex, and Scaphander for pyriform species lacking a callus and a wing.

In the absence of phylogenetic analysis of this group it is difficult to determine the relationships and whether Scaphander , Bucconia , Sabatia and Sabatina are each monophyletic. The presence of a parietal callus appears to be a synapomorphy grouping some of the species of Cylichnidae , although this needs to be confirmed with a phylogenetic analysis. Therefore the name Sabatia , the oldest available for the group of species having a parietal callus will provisionally be used as valid, and Sabatina is regarded as a synonym.