First record and description of three new species in the land snail genus Diplommatina Benson, 1849 (Caenogastropoda, Diplommatinidae) from Satun Province, Thailand Author Boonmachai, Tuangthong Ph. D. ' s Degree Program in Biology (International Program), Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand Author Bergey, Elizabeth A. https://orcid.org/0000-0002-7160-6590 Department of Biology, Faculty of Science, Chiang Mai University 50200, Thailand Author Nantarat, Nattawadee https://orcid.org/0000-0003-3317-0041 Ph. D. ' s Degree Program in Biology (International Program), Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand n_nantarat@yahoo.com text Zoosystematics and Evolution 2023 2023-03-07 99 1 195 207 http://dx.doi.org/10.3897/zse.99.99030 journal article http://dx.doi.org/10.3897/zse.99.99030 1860-0743-1-195 E28DD35A30EA4C53B5A6F0A80CA0CFC0 C59B2291F71D52B89499FD9433B4B57E Diplommatina bulonensis Boonmachai & Nantarat sp. nov. Figs 2A , 3A-C Type material. Holotype CMUZ 9050001 (Fig. 2A ); Shell measurements: SH = 2.72 mm, SW = 1.27 mm, AH = 0.94 mm, AW = 0.91 mm, W = 6 1/2. Paratypes CMUZ 9050002-9050006 (5 shells); Shell measurements: SH = 2.58-2.82 mm, SW = 1.26-1.34 mm, AH = 0.97-1.04 mm, AW = 0.92-1.03 mm, W = 6 1/2-7 1/2. Figure 2. Shell morphology of Diplommatina from Satun Province. A. D. bulonensis sp. nov. (Holotype CMUZ 9050001; Bulon Pai Island); B. D. laemsonensis sp. nov. (Holotype CMUZ 9050019; Laem Son Hill); C. D. prakaiphetensis sp. nov. (Holotype CMUZ 9050066; Prakaiphet Hill); D. D. naiyanetri (CMUZ 905090; Tarutao Island); E. D. canaliculata (CMUZ 9050158; Tharn Pliew Waterfall). Type locality. Thailand, Satun Province, La-ngu District, Bulon Pai Island on limestone rocks and under leaves, 6°49'53.3"N , 99°35'19.5"E , 22 December 2020, coll. T. Booonmachai. Other material examined. Thailand , Satun Province ; La-ngu District , Bulon Pai Island , 6°49'53.3"N , 99°35'19.5"E , 22 December 2020 : CMUZ 9050007-9050016 (10 shells); La-ngu District , Bulon Pai Island , 6°49'53.3"N , 99°35'19.5"E , 15 February 2022 : CMUZ 9050017-9050018 (2 shells) . Etymology. The specific epithet bulonensis is an adjective referring to the type locality (Bulon Pai Island in Satun Province, Thailand). Differential diagnosis. Among approximately 400 species of Diplommatina , the new species is most similar to D. conditioria Maassen, 2007, D. baliana Fulton, 1899, D. maduana Laidlaw, 1949, D. gomantongensis Smith, 1894 and D. antheae Vermeulen, 1993 (Table 1 ). Typical characteristics shared by D. bulonensis with all these species are shell dextral with a slender fusiform shape with rather evenly rounded sides, radial ribs not sinuous, constriction situated halfway on the parietal side of the peristome and aperture round. However, D. bulonensis sp. nov. differs from D. gomantongensis and D. antheae by the presence of a transverse palatalis and an inconspicuous columellar denticle in the aperture (Fig. 4A ). D. bulonensis sp. nov differs in the combination of shell height, shell width, aperture height and aperture width from D. maduana and D. antheae (Table 1 ). D. bulonensis sp. nov differs from D. conditioria and D. maduana in the number of whorls (Table 1 ) and differs from D. maduana , D. gomantongensis , D. antheae and D. baliana in the number of radial ribs/0.5 mm on the penultimate whorl (Table 1 ). D. bulonensis sp. nov has fewer radial ribs on body whorls above the aperture than D. conditioria (12-13 vs. 16 ribs/1 mm) ( Maassen 2007 ). Moreover, it differs from D. baliana in having a columella fold. Description. Shell dextral, fusiform, convex and red rushes or red-orange in color (Figs 2A , 3A ). Penultimate whorl slightly wider than body whorl, side flat. Spire conical with slightly convex sides. Suture impressed. Constriction level with the middle parietal side of the peristome, with three lamellae: one parietalis very distinct, one distinct and long transversal palatalis and one distinct columellaris. (Fig. 4A, B ). Protoconch smooth with dimples and about 2 1/2 whorls (Fig. 3B ). Radial ribs straight, inconspicuous but distinct, moderately spaced about 6 1/2-7 ribs/0.5 mm on the penultimate whorl (Table 1 ). The aperture slightly tilted against the coiling axis, columellar denticle slightly weak in the aperture. Peristome double, rather expanding, palatal side not sinuous, basal side and columella side weakly sinuous. Outer peristome expanded less than inner peristome, inner peristome expanded at parietalis side, with a palatal lip. Umbilicus closed. Operculum multispiral, flat, corneous, transparent, slightly concave, outer surface smooth, inner surface smooth with raised peripheral circular margin (Fig. 3C ). The radula of the taenioglossate type (Fig. 5B ). The central tooth round and flat with seven cusps of similar size. The basal plate of the central tooth, cuspate and small. The lateral teeth with five cusps. The marginal teeth with inner and outer teeth, the inner teeth with seven small cusps and the outer teeth with five cusps and larger than the inner teeth (Fig. 5B ). Figure 3. Scanning electron microscope of shell morphology, protoconch and operculum of Diplommatina new species. A-C. D. bulonensis sp. nov. (Bulon Pai Island); D-F. D. laemsonensis sp. nov. (Laem Son Hill); G-I. D. prakaiphetensis sp. nov. (Prakaiphet Hill). Figure 4. Shell internal terminology of new species genus Diplommatina from Satun Province under the stereo microscope and the drawing. A, B. D. bulonensis sp. nov. (Bulon Pai Island); C, D. D. laemsonensis sp. nov. (Laem Son Hill); E, F. D. prakaiphetensis sp. nov. (Prakaiphet Hill). Figure 5. Radular morphology of Diplommatina . A. Diplommatina laemsonensis sp. nov. (Laem Son Hill); B. Diplommatina bulonensis sp. nov. (Bulon Pai Island); C. Diplommatina prakaiphetensis sp. nov. (Prakaiphet Hill). Colours show the position of the teeth of the radula; blue: central tooth, yellow: the basal plate of the central tooth, green: lateral teeth, pink: inner marginal teeth, and red: outer marginal teeth.