Chilonopsis aurisvulpina ( Holten, 1802 ), 1995

Gerlach, Justin, Griffiths, Owen, Hume, Julian P., Louchart, Antoine, Sorrel, Philippe & Cairns-Wicks, Rebecca, 2025, Diversity of the extinct land snail genus Chilonopsis of St Helena (Mollusca: Gastropoda: Achatinidae), European Journal of Taxonomy 1007, pp. 176-210 : 184-191

Chilonopsis aurisvulpina ( Holten, 1802)

Figs 4a , 5–6 , 7a–b

Auris vulpina Chemnitz, 1795: 287 , pl. 210 figs 2086–2087 (non binomial).

Voluta auris-vulpina Holten, 1802: 45 .

Melania Nonpareil Perry, 1811 : pl. 29 fig. 4.

Bulimus (Pachyotus) alopecotis Beck, 1838: 56 (replacement name for Voluta auris-vulpina ). Chilonopsis sulcata Fischer von Waldheim, 1848: 236 .

Bulimus relegatus W.H. Benson, 1851: 31 .

Bulimus darvinianus Forbes, 1852: 4 , pl. 5 fig. 1.

Bulimus auris-muris (non Moricand) Shuttleworth, 1852a: 200 (preoccupied).

Bulimus auris-myoxi Shuttleworth, 1852b: 289 (replacement name for Bulimus auris-muris ).

Voluta auris-vulpina – Dillwyn 1817: 503. — Reeve 1849: pl. 30 fig. 180.

Helix auris-vulpina – Férussac 1822: 57.

Pupa Auris vulpina – Gray 1825: 413.

Bulimus auris-vulpina – Griffith & Pidgeon 1834: 596, pl. 37 fig. 7. — Lamarck 1838: 257. — Deshayes 1839: 257. — Küster 1844: 39. — Pfeiffer 1848: 93; 1853: 371; 1854: xii; 1859: 440; 1868: 77. — Jeffreys 1872: 264. — Melliss 1875: 121. — Wollaston 1878: 547 (including var. subspiralis , obliteratus). — Smith 1892: 265.

Cochlogena auris-vulpina – G.E. Sowerby I 1844: 155.

Bulimus relegatus – Pfeiffer 1853: 417; 1868: 123. — Melliss 1875: 122.

Bulimus auris-vulpina – Wollaston 1878: 547.

Bulimus Darwinianus – Wollaston 1878: 549 (misspelling).

Buliminus (Pachyotus) auris vulpina – Kobelt 1902: 656.

Chilonopsis nonpareil – Pilsbry 1904: 174. — Crowley & Pain 1977: 553. — Schileyko 1999: 532.

Chilonopsis nonpareil var. darvinianaus – Pilsbry 1904: 176.

Chilonopsis (Chilonopsis) non pareil – Germain 1931: 169.

Chilonopsis nonpareil darvinianus – Crowley & Pain 1977: 555.

Chilinopsis [sic] nonpareil – Woodward 1991: 4.

Chilonopsis aurisvulpina – Petit 2003: 41. — Petit & Coan 2008: 244.

Diagnosis

The largest Chilonopsis (height 33.1–48.4 mm), unique in having the body whorl angled near the shoulder and with very prominent sutural bosses. The lip is sinuous and there is usually a nodule on the parietal callus; the lip and callus are unusually thickened.

Type material

Lectotype of Auris vulpina (here designated)

SAINT HELENA • shell; “ China ”; Spengler collection; NHMD- 1725954 ( Fig. 5a ).

Remarks

This is the shell figured ( Fig. 5b ) by Chemnitz (1795: 287, pl. 210 figs 2086–2087); the description was also based on two immature specimens, which have not been located. The immature specimens were bought from the Humfredianum Museum auction in Hamburg in 1794; the auction catalogue gave their origin as Saint Helena ( Holten 1802). The figured specimen was supposedly from China. We designate this specimen as the lectotype ( Fig. 5a ). In addition to the type material, Spengler had a second specimen labelled “ St. Helena, 20 feet deep in the rock” ( NHMD- 1725961), this is worn, with the lip broken.

Type of Melania Nonpareil Not located, Perry’s (1811) figure ( Fig. 5c ) appears to be a copy of Chemnitz’s figure of Auris vulpina but he states that it was ‘from a specimen in Mr. Lloyd’s Museum.’ (probably William Horton Lloyd 1784–1849).

Type of Chilonopsis sulcata

Not located; ‘St. Jago Americae meridionalis’, figured by Fischer von Waldheim (1848) ( Fig. 5d ).

Holotype or syntype of Bulimus relegatus

SAINT HELENA • Lt. Lefroy ; UMZC I.105005 ( Fig. 5e ).

Remarks

In the Robert McAndrew collection, ex W.H. Benson ( Preece et al. 2022). It is unclear whether this is the holotype or a syntype: Preece et al. (2022) listed it as a syntype, but the original description gives no indication as to whether it was based on one or more specimens. This is the only specimen known to have been collected by Lefroy.

Holotype of Bulimus auris-myoxi

SAINT HELENA • no locality; ex Marguiger 1845; NMBE-WL-19055 ( Fig. 5f ). Figured by Neubert & Gosteli (2003).

Syntypes of Bulimus darvinianus

SAINT HELENA • 2 shells; collected by Edward Alexander; NHMUK-PI G 25274-5 ( Fig. 5g –h ). Figured by Forbes (1852: pl. 5 fig. 1); presented by E. Alexander to Museum of Practical Geology , later transferred to NHMUK .

Other material examined

20 th century specimens include one worn specimen found in 1964 ( Woodward 1991). Crowley & Pain (1977) noted that none could be found in Turton’s localities by the MRAC Expedition (Flagstaff, Sugarloaf, Barn) and thought that the last remaining specimen was the one taken in 1972 by A. Loveridge at 300 m on the slopes of Bencoolen (Dry Gut), all others having been lost through erosion. However, the MRAC expedition concentrated only on recent and living animals, and the discovery of new material demonstrates that specimens can still be found.

Typical form

SAINT HELENA • 3 shells; coll. J.S. Phillips; ANSP MAL 330769 • 3 shells; ex T.B. Wilson; ANSP MAL 330770 • 1 broken shell; CM 62.6934 • 1 shell; Sugarloaf Ridge ; ex Walton 10855; DMNH 142088 • 1 shell; FMNH 36152 • 1 shell; FMNH 48078 • 1 shell; on ridge leading to Bryan’s rock; 27 May 1963; A. Loveridge leg.; FMNH 173184 • 1 shell; Sugarloaf Ridge , N coast facing E.; elev. ca 1000 ft; 30 Oct. 1963; A. and M. Loveridge leg.; FMNH 173185 • 2 shells; Sugarloaf Ridge , N coast facing E; A. and M. Loveridge leg.; FMNH 173186 • 1 shell; Sugarloaf Ridge from bases of Suaeda fruticosa ; 30 Oct. 1963; A. Loveridge leg.; FMNH 173190 • 1 shell; LIV • 2 shells; off west coast; MCZ 141183 • 10 shells; Deadwood Plain ; elev. 1500 ft; 1 Feb. 1949; MCZ 203239 • 1 shell; MCZ 381633 • 1 shell; Spence , Layard and Darbyshire collections; MM • 1 shell; A. Loveridge leg.; MRAC • 6 shells; Prosperous Bay Plain; 1995; P. and M. Ashmole leg.; MSH (1 used for SEM – Fig. 7a–b ) • 1 spec.; Dry Gut ; Aug.–Sep. 2022; “AtlantAves” leg., MSH • 1 shell; transferred from Museum of Practical Geology , presented by E. Alexander; NHMUK-PI G25278 • 1 shell; J. Brown collection 1860; NHMUK G25284-6 • 8 shells; W.H. Turton leg.; NHMUK 1892.2.24.1-7 • 5 shells; NHMUK 1892.2.24.10- 5 • eggs; W.H. Turton leg.; NHMUK 1892.2.24.166-170 • 2 shells; Trechmann collection; NHMUK 2176 • 17 shells; NHMUK • 1 shell; Sugarloaf Ridge ; Tomlin collection ex Blok collection; NMW • 1 shell; Putzeys collection; RBINS:IG.27761-INV.66549 • 1 shell; P. Dupuis collection ex Fulton; RBINS: IG8907-HIST.5 • 5 shells; J.C. Coops leg.; Sep. 1916; RMNH.MOL.269631-3 • 1 shell; Sowerby and Fulton collection (original provenance not documented); SANBI MB-A034375 • 4 shells; SANBI MB-A054185 • 4 shells; J.R. Tomlin leg.; UMMZ 141296 • 2 shells; USNM 104990 • 1 shell; USNM 126261 • 8 shells; USNM 703393 • 4 shells; USNM 709840 • 2 shells; USNM 713598 .

“ darvinianus form”

SAINT HELENA • 2 shells; FMNH 126262a • 1 shell; Sugarloaf Ridge, N coast facing E; elev. ca 1000 ft; 1963; A. and M. Loveridge leg.; FMNH 173185 • 1 shell; Sugarloaf Ridge ; 1963; A. Loveridge leg.; FMNH 173190 • 1 shell; Sugarloaf Ridge; W.H. Turton leg.; Darbyshire collection; MM • 1 shell; Woodward and McAndrew collections; UMZC • 1 shell; W.H. Turton leg.; USNM 126262 • 2 shells; USNM 707830 • 4 shells; USNM 710416 .

Description

The largest Chilonopsis (33.1–48.4 mm high; Table 1 ). Shell moderately thin, often solid in subfossil specimens. Usually ovate, sometimes narrowly ovate to elongate. 6.5–7 convex whorls, body whorl high shouldered, angled at shoulder and margin. Protoconch of 0.75 whorls, ornamented with 5–6 spiral striae, which are only distinct in the freshest specimens ( Fig. 7a ). Teleoconch with low, coarse radial ridges raised into bosses at suture, overlain by fine radial ridges from second whorl. Faint spiral striae on first whorl, only distinct on the bosses, giving a granular appearance to the spire. On all other whorls these develop into strong, well separated spiral cords ( Fig. 7b ). Umbilicus compressed or closed. Lip expanded and thickened, curved inwards in middle part, compressing aperture. Columella slanting, obliquely subtruncated. Parietal callus thick, usually with a recessed parietal nodule of variable prominence.

Colour in the best-preserved specimens varying from whitish (probably faded) to red-brown, aperture orange-red, columella pink, parietal callus orange-red.

A variable species; four varieties have been recognised by Wollaston (1878) and listed by Pilsbry (1904):

Typical form – trochiform with whorls angled near the suture, coarse radial striae, umbilicus largely obscured, lip thickened, right margin bends inwards, aperture lacking nodules

“var. subspiralis ” – as typical form but with more pronounced spiral striae and weaker radial ridges, closed umbilicus, a parietal nodule within the aperture

“var. obliteratus ” – as typical form but whorls less angled, lip thinner and straighter on outer margin, umbilicus covered, a low parietal nodule deep within the aperture

“var. darvinianus ” – narrow with an elongate spire, smoother, umbilicus closed, parietal tubercle usually well developed

“ Var. darvinianus ” was kept as a subspecies by Crowley & Pain (1977) as it was ‘remarkably constant in form and size’ but varied in nodule development. All the varieties were sympatric on the Sugarloaf where they intergrade. As they were sympatric and lacked clear dividing lines none of the varieties can be maintained as a subspecies.

Distribution

Eastern third of the island ( Fig. 11 ): behind Longwood ( Blofeld 1852); all along Sugarloaf Ridge (over 30 specimens from Turton, in Smith 1892; Wollaston 1878); Flagstaff ( Wollaston 1878); towards The Barn ( Wollaston 1878); Dry Gut ( Woodward 1991; new); ridge leading to Bryan’s Rock (FMNH 173184); Deadwood Plain (MCZ); Prosperous Bay Plain (MSH). Melliss (1875: 122) recorded it “embedded in the surface-soil in the ravines formed by rain, on the north-eastern quarter of the Island, at altitudes from 1200 to 1700 feet above the sea.”

Both the typical variety and the rarer darvinianus form were found together on Sugarloaf, Flagstaff and Barn ( Wollaston 1878).

Extinct; never recorded living.

Remarks

According to Petit & Coan (2008), Holten’s (1802) list validates Chemnitz’s non-binomial names, making Voluta auris-vulpina Holten, 1802 available. Accordingly, the correct name for this species is Chilonopsis aurisvulpina ( Holten, 1802) .

Bulimus relegatus W.H. Benson, 1851 was synonymised with C. helena by Wollaston (1878) and this was followed by Crowley & Pain (1977) and Preece et al. (2022), however it falls within the range of variation of the “ darvinianus ” form of C. aurisvulpina . Thus, we consider it a junior synonym of C. aurisvulpina .

Melliss (1875: 121) described possible live records from the late 19 th century: “Being exceedingly anxious to discover if this creature still lived, I explored the locality very carefully, about four years ago, and enlisted the sympathies of some of the peasantry in my cause. The wife of a labouring man, living in a small cottage in the valley at the back of Longwood, assured me that she often saw them alive, and that after heavy rains they came out of the earth and fed upon the Hottentot Fig plants. Thinking she meant the common garden snail ( Helix aspersa ), so abundant in the same neighbourhood, I examined her on this point; but so positive was she that she had seen the real, living Bulimus auris-vulpina , and that her children had used them as playthings, which statement the children confirmed, that I felt scarcely able to doubt their existence still in a living state. Possibly some few may lurk hidden somewhere; but, considering the changes which have taken place in the physical character of that part of the Island, and that the offer of a liberal reward to my sanguine acquaintance failed to produce a living specimen, I must confess that I am still sceptical upon this point.”

Darwin (1844: 90) collected most of his specimens from the north-west side of Flagstaff Hill: “It is very remarkable that all the shells of this species found by me in one spot, form a distinct variety, as described by Mr. Sowerby, from those procured from another locality by Mr. Seale… have shown in my Journal, that the extinction of these land-shells possibly may not be an ancient event; as a great change took place in the state of the island about 120 years ago, when the old trees died, and were not replaced by young ones, these being destroyed by the goats and hogs, which had run wild in numbers, from the year 1502.”

Figures

Fig. 4. Species of Chilonopsis. a. C. aurisvulpina (Holten, 1802) (NHMD-172594). b. C. helena (Quoy & Gaimard, 1832) (NHMUK 20240185). c. C. blofeldi (Forbes, 1852) (NHMUK). d. C. lanceoloideus sp. nov., holotype (NHMUK 20240171). e. C. exulatus (Reeve, 1849) (UMZC I.105095). f. C. subtruncatus (E.A. Smith, 1892) (NHMUK 92.2.24.224-8). g. C. turtoni (E.A. Smith, 1892) (NHMUK 1892.2.24.209-218). h. C. subplicatus (G.B. Sowerby I, 1844) (MSH). i. C. melanioides (Wollaston, 1878) (ANSP 97326). Scale bar = 25 mm.

Fig. 5. Chilonopsis aurisvulpina (Holten, 1802) types. a. Auris vulpina Chemnitz, 1795, lectotype figured by Chemnitz (NHMD-1725954). b. Auris vulpina figure (Chemnitz 1795). c. Melania Nonpareil Perry, 1811 figure (Perry 1811). d. Chilonopsis sulcata Fischer von Waldheim, 1848 figure (Fischer von Waldheim 1848). e. Bulimus relegatus W.H. Benson, 1851 (UMZC I.105005). f. Bulimus Auris-Myoxi Shuttleworth, 1852, holotype (NMBE-WL-19055). g–h. Bulimus darvinianus Forbes, 1852, syntypes (NHMUK-PI G 25274-5). Scale bar = 50 mm. Photos: a = M. Vinther Sørensen, NHMD; c = NHMUK; e = UMZC; f = E. Neubert, NMBE.

Fig. 6. Chilonopsis aurisvulpina (Holten, 1802) variation in a single sample (NHMUK un-numbered). Scale bar = 20 mm.

Fig. 7. Sculpture of species of Chilonopsis. a–b. Chilonopsis aurisvulpina (Holten, 1802) (Prosperous Bay Plain, P. & M. Ashmole, 1995), protoconch (a) and spire (b). c–d. Chilonopsis helena (Quoy & Gaimard, 1832) (Turks Cap summit, “AtlantAves”, Aug. 2022) scanning electron micrographs of protoconch (c) and body whorl (d). e. Chilonopsis lanceoloideus sp. nov. (Castle Rock Plain, P. & M.Ashmole, 1995) scanning electron micrograph of protoconch and spire. Scale bars = 500 μm.

Fig. 11. Distributions of species of Chilonopsis Fischer von Waldheim, 1848.