Cyclophorus jourdyi Morlet, 1886 [93]

Conchological description. Medium-sized Cyclophorus species, overall shell shape rounded, aperture typically circular. Shell height 21.8 to 31.1 mm (mean = 27.6 mm), shell breadth 25.1 to 34.0 mm (mean = 30.6 mm) (sub-group I: shell height 26.0 to 31.1 mm

(mean = 28.4 mm), shell breadth 28.0 to 34.0 mm (mean = 31.3 mm); sub-group II: shell height 21.8 to 24.8 mm (mean = 23.0 mm), shell breadth 25.1 to 29.1 mm (mean = 26.8 mm)). Number of whorls 5 to 5.5 (sub-group I: 5.25 to 5.5; sub-group II: 5). Early whorls with or without bluish colouration (sub-group I: with or without bluish colouration; sub-group II: with bluish colouration). Shape of body whorl usually uncompressed or slightly compressed; well-rounded (sub-group I: uncompressed or slightly compressed; well-rounded; sub-group II: uncompressed, slightly compressed or compressed; well-rounded). Lip usually reflected and simple (sub-group I: usually reflected and simple; sub-group II: reflected and simple). Lip colour white or ivory (sub-group I: ivory or white; sub-group II: white). Wing-shaped projection at columellar margin present and pronounced. Peripheral band dark brown. Colour pattern generally variable. Typical elements of pattern above position of peripheral band: flames, zig-zag stripes and spots in different shades of brown or in white (sub-group I: flames, zig-zag stripes and spots in different shades of brown or in white; sub-group II: flames and zig-zag stripes in darker shades of brown). Typical elements of pattern below position of peripheral band: spiral lines, spiral bands and flames in darker shades of brown (sub-group I: spiral lines, spiral bands and flames in darker shades of brown; sub-group II: spiral lines and flames in darker shades of brown).

Displayed specimens. VNM042 (Fig 7a; sub-group I), specimen in ethanol; NHMUK 20110608/3; GenBank accession numbers MG720878 (COI), MG720928 (16S), MG720978 (28S); male individual; shell height 27.0 mm, shell breadth 29.8 mm, number of whorls 5.25. VNM043 (Fig 7b; sub-group I), specimen in ethanol; NHMUK 20110608/4; GenBank accession numbers MN153319 (COI), MN153368 (16S), MN153415 (28S); female individual; shell height 28.1 mm, shell breadth 29.7 mm, number of whorls 5.5. VNM 044 (Fig 7c; sub-group I), specimen in ethanol; NHMUK 20110608/2 (ethanol-preserved frozen tissue sample NHMUK Barcode 014041336); GenBank accession numbers MG720877 (COI), MG720927 (16S), MG720977 (28S); female individual; shell height 26.5 mm, shell breadth 29.6 mm, number of whorls 5.25. VNM045 (Fig 7d; sub-group II), specimen in ethanol; NHMUK 20110603/2; GenBank accession numbers MG720876 (COI), MG720926 (16S), MG720976 (28S); male individual; shell height 21.8 mm, shell breadth 25.1 mm, number of whorls 5. VNM046 (Fig 7e; sub-group II), specimen in ethanol; NHMUK 20110603/1 (ethanol-preserved frozen tissue sample NHMUK Barcode 014041335); GenBank accession numbers MN153320 (COI), MN153369 (16S), MN153416 (28S); sex of individual not determined (parts of soft body damaged); shell height 24.8 mm, shell breadth 29.1 mm, number of whorls 5.

Locality and sampling data. VNM042, VNM043, VNM044: Vietnam, Quang Ninh, Ha Long, Ha Phong ward (20.96638˚, 107.16610˚); 25 May 2011; leg. Hao Van Luong, Fred Naggs & Sang Van Pham. VNM045, VNM046: Vietnam, Quang Ninh, Son Duong commune (21.06693˚, 106.98883˚); 24 May 2011; leg. Hao Van Luong.

Diagnosis. Cyclophorus jourdyi can be differentiated from all herein characterised Cyclophorus species based on DNA sequence data. Diagnostic nucleotide substitutions of the cytochrome c oxidase subunit I (COI) gene: 184:C, 325:C, 415:T, 458:G (numbers indicate the position in the studied COI fragment).

Remarks. The studied syntypes (MNHN-IM-2000-33830, MNHN-IM-2000-33831 and RBINS I.G.10591/MT.902, the latter labelled as paratype) resembled sub-group I and II in size, shape and colouration. No specific type locality is given in Morlet [93] besides “Tonkin”, where all taxa from the respective publication have been described from. In Morlet [109], however, the following locality is given for this species: “Tonkin: Ha Long Bay and Elephant Mountain” (original: “Tonkin: baie d’Halong et montagne de l’Éléphant”), which includes “Ha Long Bay / Tonkin” (original: “Baie d’Halong / Tonkin”) given on a label of the Brussels syntype (the Paris syntypes’ labels only state “Tonkin” (original: “Tonkin” and “Tonquin”)) and the location where our studied samples of sub-group I were collected. This species corresponds to lineage 07 in Oheimb et al. [6]. We regard the material from central Vietnam, which has been determined as C. jourdyi by Nantarat et al. [47] (also included in the phylogenies of [6] and this study, herein VNM029), as belonging to a different species. The studied material of C. jourdyi has been found in southern Quang Ninh province (sub-groups I and II) (Fig 4). None of the other herein characterised species is known to occur sympatrically with this species.