Granata Cotton, 1957

Herbert, D. G., 2012, A revision of the Chilodontidae (Gastropoda: Vetigastropoda: Seguenzioidea) of southern Africa and the south-western Indian Ocean, African Invertebrates 53 (2), pp. 381-381 : 480-482

Genus Granata Cotton, 1957

Granata: Cotton 1957: 126 . Type species: Stomatella imbricata Lamarck, 1816 , by original designation.

Nomenclatural remarks: Cotton (1957), believing Stomatella auricula Lamarck, 1816 to be the type species of Stomatella Lamarck , 18163, proposed a new generic taxon, Granata , for Stomatella imbricata Lamarck, 1816 . However, there have been differing opinions concerning the type species designation for Stomatella . Early workers such as Thiele (1924, 1929) and Wenz (1938), following Gray (1847) and Pilsbry (1890 in 1890–91), believed it to be S. imbricata and, recognising the true affinities of that species, placed Stomatella near Euchelus and Danilia . In contrast, most recent authors (e.g. Keen 1960; Hickman & McLean 1990) have followed Cotton (1957) who observed that Anton had designated Stomatella auricula as the type species of Stomatella , in his

3 Although Lamarck (1816) is traditionally cited as the author of Stomatella , the genus has recently been credited to Bowdich (1822) ( Bouchet & Rocroi 2005). This stems from the fact that Lamarck’s plate of Stomatia and Stomatella in his Tableau Encyclopédique ( Lamarck 1816: pl. 450) has no associated legend and thus no species are listed under these names and it is not evident which figures he considered to belong to the respective genera. The legend is taken to have been eventually published in 1827 ( Evenhuis 2003). Prior to this, however, Lamarck clarified his concept of these genera in his Histoire naturelle des animaux sans vertèbres (Lamarck 1822; April), where he described a number of species, but this was pre-dated by a publication in which Bowdich (1822; February) discussed Stomatella , citing and illustrating a single species, Stomatella imbricata , thus suggesting that Bowdich was the first to validly propose the genus. However, in reallity a legend was published in 1816 for the Stomatia and Stomatella plate in the

Verzeichniss der Conchylien ( Anton 1838, but cited as 1839), and that this pre-dated Gray’s (1847) more widely known designation of S. imbricata . Macpherson and Gabriel (1962) claimed that no such designation existed in the Verzeichniss der Conchylien and believed Granata to be an ‘absolute [objective] synonym’ of Stomatella . Iredale and McMichael (1962) listed S. imbricata as the ‘logotype’ (type species by subsequent designation) of Stomatella , citing Dujardin in Dictionnaire Universel d’ Histoire Naturelle (d’Orbigny 1839–1849) and giving a date of ‘ ante 1845’. The most recent analysis of the dates of publication for the various volumes and livraisons of d’Orbigny’s Dictionnaire ( Evenhuis 1990), however, gives the date for volume 12, livraison 133, pages 1–64 (entries Stellion to Strombides in the dictionary, Stomatella on p. 47) as 9 September 1848.

Examination of Anton’s Verzeichniss shows that a type designation is in fact present, though somewhat concealed. In the introductory pages to this work, Anton stated “… den Gattungen (deren typusart mit Versalbuchstaben gedruckt ist)” [“…the genera (whose type species are printed in capital letters)”] ( Anton 1838: vi) and entry 1222 under Stomatella is printed “LUTEA = St. auricula Lam. = Patella lutea L.”. However, since Stomatella lutea was not one of the nominal species originally included by Lamarck (1916) in Stomatella , it is not eligible for subsequent designation as the type species (ICZN 1999: Art. 69.1). This not withstanding, since Anton clearly indicated that he considered Patella lutea to be a synonym of Stomatella auricula , which was one of the species originally included in Stomatella , this is to be considered a valid fixation of the latter species as the type species of the genus (ICZN 1999: Art. 69.2.2). Dated 1838 ( Cernohorsky 1978 a), it is evidently the earliest designation available. Like Anton, Lamarck himself considered Patella lutea and Stomatella auricula to be synonymous (Lamarck 1822: 210), though Pilsbry (1890 in 1890–91) believed P. lutea to be an unidentifiable entity.

Remarks: Hickman (1998) believed Granata to be a monotypic genus endemic to the southern half of Australia. However, I follow other recent authors (e.g. Sasaki 2000; Poppe et al. 2006) in referring additional auriform chilodontids to this genus. While these may not be as depressed and haliotiform as the type species, they almost certainly belong to the same lineage. With these taxa included in Granata , it is evident that the genus is widely distributed in the Indo-West Pacific. In addition to being conchologically similar, G. sulcifera , like G. imbricata , has an enlarged right hypobranchial gland and secretes a noxious white mucus when irritated, and has a similar radula morphology.

The relationship of Granata and Stomatolina Iredale, 1937 (type species Stomatella rufescens Gray, 1847 , by original designation) needs to be further investigated. Both stomatelline and chilodontid taxa have been referred to Stomatolina .Although the matter could be easily resolved by examination of the radula and external anatomy, the difficulty lies in obtaining reliably identified specimens of S. rufescens . On the evidence available (Iredale 1937), it seems more probable that Stomatolina is stomatelline, perhaps close to Pseudostomatella Thiele, 1924 .

Though perhaps related to Granata , species of Hybochelus Pilsbry, 1890 (type species Stomatella cancellata Krauss, 1848 , by original designation) differ in having a less expanded last adult whorl, an open umbilicus (typically) which is bordered by somewhat stronger cords, and an operculum which almost completely closes the aperture (pers. observ. Hybochelus mysticus (Pilsbry, 1890)) . The genus occupies conchological morphospace somewhat intermediate between that of typical Euchelus and Granata . As indicated earlier (see Excluded taxa, p. 398), Krauss’s Stomatella cancellata is an extralimital species and is not included in this revision.