Pupa solidula (Linnaeus, 1758)

(Figs. 2A, 3, 4A, 5A)

Bulla solidula Linnaeus, 1758: 728–729. Type locality: undetermined.

Pupa grisebla R̂ding, 1798: 110. Type locality: undetermined.

Dactylus punctatus Schumacher, 1817: 234. Type locality: undetermined.

Type material. Bulla solidula, Pupa grisebla, and Dactylus punctatus —original type material untraceable, neotype (here designated), 20 mm long (shell) (MNHN IM-2013-86152, isolate KF70), Strait of Baron, Koumac, New Caledonia (20°33.8′S, 164°10.3′E) [Koumac 2.1 stn. KR644, soft bottom], 29 Sep 2018.

Material examined. Interior of the Great Reef of Koumac, next to the Strait of Koumac, New Caledonia (20°39.1′S, 164°13.4′E), 13–15 m depth [Koumac 2.1 stn. KR601, coarse sand], 3 Sep 2018, 1 specimen 13 mm long (shell) (MNHN IM-2013-86155, isolate KF65). Koumac lagoon, New Caledonia (20°36′S, 164°14.9′E), 11 m depth [Koumac 2.3 stn. KD502], 28 Oct 2019, 1 specimen 16 mm long (shell) (MNHN IM-2013-86162). Interior of the Great Reef of Koumac, New Caledonia (20°39.2′S, 164°13.5′E), 10 m depth, [Koumac 2.3 stn. KD516], 1 Nov 2019, 1 specimen 20 mm long (shell) (MNHN IM-2013-86163). Koumac lagoon, New Caledonia (20°43.8′S, 164°16.4′E), 11–12 m depth, [Koumac 2.3 stn. KD578], 19 Nov 2019, 1 specimen 12 mm long (shell) (MNHN IM-2013-86164).

External morphology. Body oval, about the same width throughout (Fig. 2A). Cephalic shield deeply notched longitudinally, with two elongate posterior extensions covering anterior end of shell. Foot extending beyond cephalic shield laterally. Body color translucent white, with opaque white dots scattered all over dorsal surface of cephalic shield, foot. Shell solid, narrow to oval, elongate (Fig. 3), widest at mid-length, sides convex, rounded anterior end. Body whorl large, about 6/7–7/8 of total length. Spire elongate, conical, with four whorls. Suture channeled. Aperture elongate, wider anteriorly, narrowing abruptly towards posterior end, ending at 1/7 of the posterior end of first whorl. Columellar margin thickened, slightly oblique, with single large, channeled anterior fold starting at anterior end of aperture. Apex of all specimens examined damaged, protoconch not observed. Sculpture composed of numerous punctuated spiral grooves. Punctuations conspicuous, irregular, oval, situated next to each other, fused, within each groove. Grooves separated by gaps wider than grooves. Shell color white (orange-brown in New Caledonia species as they are covered with fine silt), checkered with dark grey to black, square to oval patches, situated on gaps between punctuated spiral grooves all over shell. Irregular white pigment among some of the dark patches. One band on body whorl with smaller patches in some specimens. Posterior whorls orange-brown with no dark patches. Punctuated spiral grooves often edged in orange-red. Operculum translucent to ochre, oval to elongate, with faint longitudinal striations (Fig. 4A).

Internal morphology. Reproductive system with large, elongate penis (Fig. 5A), otherwise indistinct. Digestive system with elongate buccal mass (Fig. 6A). Oral tube conical, connected to curved buccal bulb. Salivary glands, esophagus, connected on proximal end of buccal bulb. Radular formula 111 × 4.0. 4 in a 13 mm long specimen (MNHN IM- 2013-86155). Lateral teeth similar in shape (Fig. 7A). Teeth triangular, with broad bases; elongate, curved, sharp cusp; 6–7 denticles similar to cusp in shape, shorter. Jaws with elongate elements, bearing 2–6 finger-like projections apically, normally arranged on same plane (Fig. 8A).

Geographic range. Widespread in the tropical Indo-West Pacific region (Rudman, 1998a; Gosliner et al., 2018).

Remarks. Linnaeus (1758) introduced the name Bulla solidula based on an illustration by Bonanni (1681: fig. 143) and the following description: “bubble shell oblong-oval, dark striated, spire acute elevated, columella biplicated.” Linnaeus’ (1758) description clearly corresponds to the modern usage of the name Pupa as it refers to the two columellar folds, but it is not detailed enough to determine to which of the currently recognized species it corresponds. The illustration by Bonanni (1681, fig. 143) is also very crude and difficult to interpret, the aperture is not visible and the teleoconch possesses 7 whorls, each with about 10 dark, narrow longitudinal stripes. This illustration resembles the characteristics of Acteon virgatus (Reeve, 1842) but it is much more elongated. Bonanni (1681: 203) also included a short description: “turbo similar to the ‘Garagoo’ [= Aporrhais pespelecani (Linnaeus, 1758)?], light-colored, rarely green.” Later, Linnaeus (1764: 590) provided a more detailed description of this species, including information on the color of the shell: “lined with white bands, wavy red longitudinally,” which appears consistent with the current usage of Acteon virgatus (Reeve, 1842) or perhaps Maxacteon flammeus (Gmelin, 1791). Gmelin (1791: 3437) transferred B. solidula to the genus Voluta and included several additional references, such as Linnaeus (1764) and others, but kept the reference to Bonanni (1681) and added Bonanni (1709) [the Kircher Museum catalog] both with a question mark, suggesting that Gmelin (1791) was not sure the illustrations and descriptions by Bonanni (1681; 1709) fit his interpretation of this species. As a side note, Bonanni (1709: 457) refers to the same shell (no. 143) as in Bonanni (1681) but with a somewhat different description: “Turbo white and rare, representing a snail shape, which many Spanish people call Garagoi [sic].” Other early illustrations attributed to this species by Kiener (1834, pl. 1, fig. 2) and Reeve (1842b, pl. 206, fig.7) represent a species of Pupa with a characteristic white shell checkered with reddish, brown, or black square to oval patches, and irregular white pigment among some of the dark patches. Pilsbry (1893) described and figured shell specimens similar to those illustrated by Kiener (1834) and Reeve (1842b) and transferred B. solidula to the genus Solidula. Dodge (1955) placed B. solidula in the genus Pupa and provided a comprehensive discussion of the use of the name B. solidula in the old literature, too lengthy to be included here. Recent illustrations of live animals (e.g., Rudman, 1998a; Hervé, 2010; Gosliner et al., 2018) are also consistent with the usage of the name P. solidula in the references above, except that instead of white, the shells from New Caledonia specimens are orange-brown; this is due to the presence of sticky brownish-orange silt deposited on the shell surface (pers. obs.). Although the name P. solidula has been consistently applied to the same species in the literature, the taxonomic status of the name P. solidula remains unclear, due to the lack of information in the original description (Hanley, 1855) and it has been applied to different species early on (Dodge, 1955). In order to define this nominal taxon objectively, a specimen collected in New Caledonia (MNHN IM-2013-86152, isolate KF70) is here designated as the neotype in accordance with ICZN (1999: Article 75). The name-bearing type specimen (holotype?) of P. solidula is untraceable and probably lost. According to Hanley (1855) no shells in the “Linnean Cabinet” (Linnean Society of London) agree with the original description of B. solidula. Filippo Bonanni (or Buonanni), the author of the drawing upon which the name P. solidula is based was an Italian Jesuit priest and shell collector, who was commissioned to reorganize the “Kircher Museum” (Inglehart, 2018). The specimen in question is cited in the catalogue of the “Kircher Museum” (Bonanni, 1709), indicating it was part of the collection. However, the collections of the “Kircher Museum” were dispersed among various museums in Rome and other parts of Italy and numerous attempts to locate this specimen by contacting various scholars (M. Oliverio, P. Findlen, A. Inglehart) have failed. A box of shells and fossils from “Kircher Museum” is deposited at the Museo di Anatomia Comparata “Battista Grassi” in Rome, but none of the specimens in the box belongs to a species of Pupa (M. Oliverio, pers. comm.). It can only be assumed, with the available evidence that the original type material of P. solidula is probably lost.

As mentioned above, R̂ding (1798) introduced the new name Pupa grisebla R̂ding, 1798 for the species Gmelin (1971) referred to as Voluta solidula [= Pupa solidula (Linnaeus, 1758)]. Therefore, Pupa grisebla R̂ding, 1798 is an unnecessary replacement name for P. solidula and therefore available (ICZN, 1999: Article 12.2.3), but an objective junior synonym of Pupa solidula. Also, as mentioned above, Schumacher (1817) introduced the name Dactylus punctatus Schumacher, 1817 based on a short description and references to Bulla solidula Linnaeus, 1758 [= Pupa solidula], Voluta solidula (Linnaeus, 1758) sensu Chemnitz (1787 –88: 154–156, pl. 149, fig. 1405), which is consistent with the usage of Pupa solidula, and the non-binominal name “ Auricula Midae non fimbriata ” (listed as “ Auricula punctata ”) described by Martini (1773: 124, pl. 43, figs. 440–441), which corresponds to Voluta sulcata Gmelin, 1791 [= Pupa sulcata]. Because D. punctatus appears to be based on two different species, to prevent further confusion and fix the usage of the name, the neotype of B. solidula is here designated as the neotype of D. punctatus, fixing the synonymy of these two names.

Buccinulus huttoni Kirk, 1882 was considered a synonym of P. solidula by Beu (2004), but the examination of the holotype suggests that B. huttoni is in fact a synonym of Pupa affinis (A. Adams, 1855) (see remarks of this species).