Burmochlamys fasciola Pholyotha & Panha sp. nov.

Figs 1, 2A, 3A, 5A, 7C, D, 8J-L, 10A, 11D

Material examined.

Type material. Holotype: CUMZ 14213 (Fig. 7C; width 5.6 mm, height 5.1 mm). Paratypes: Same locality as holotype: CUMZ 14214 (Fig. 7D; width 5.8 mm, height 4.9 mm), NHMUK (two shells).

Other material.

Kyankaw Mountain, Hpa-An, Kayin State, Myanmar (17°00'59.5"N, 97°42'12.4"E): CUMZ 14215 .

Type locality.

Bardai Mountain, Hpa-An, Kayin State, Myanmar (17°00'00.5"N, 97°41'41.6"E).

Diagnosis.

Shell globose and milky white with narrow yellowish brown band. Animal pale freshy-grey with five mantle extensions. Genitalia with rather short epiphallic caecum attached by thin penial retractor muscle, very short vagina, and solid at the tip of dart apparatus.

Description.

Shell (Figs 7C, D, 8J-L). Shell globose, small (width up to 6.1 mm, height up to 6.0 mm), thin, semi-translucent. Colour milky-white with a narrow yellowish brown band above periphery. Protoconch and teleoconch surface with similar sculpture. Surface of body whorl with distinct spiral furrows at regular intervals, cut by distinctly undulating radial lines (Fig. 8J-L). Whorls 6- 6½, increasing regularly; suture shallowly impressed; spire much elevated; last whorl well-rounded. Aperture obliquely crescent-shaped; peristome simple. Columellar margin simple, slightly reflected near umbilicus. Umbilicus open, narrow, and deep.

Genital organs (Fig. 10A). Atrium (at) very short or indistinct. Penis (p) moderate, cylindrical and with a thin penial sheath. Epiphallus (e1+e2) ca. three-fifths of penis length; e1 cylindrical and smaller diameter than penis and e2; e2 bulbous and ca. half of e1 length. Epiphallic caecum (ec) rather short, cylindrical and with a thin penial retractor muscle (prm) attached at tip. Vas deferens (vd) thin tube. Dart apparatus large, long cylindrical, with solid at the tip (yellow arrow in Fig. 10A), and located on atrium at vagina and penis junction. Vagina (v) very short to indistinguishable. Gametolytic sac (gs) bulbous; gametolytic duct (gd) cylindrical, moderate, slightly shorter than penis. Free oviduct (fo) ca. half of penis length, cylindrical, and encircled with thick tissue near vagina.

Radula (Fig. 11D). Teeth arranged in wide U-shaped rows with each row consisting of ~ 50 teeth. Central tooth monocuspid, large and oblong spatulate plate, and attached by two smaller triangular-shaped teeth at its base. Laterals and marginals not differentiated and monocuspid; each tooth with large and oblong spatulate plate attached by only a smaller triangular-shaped tooth at base on outer side. From inner to outer, lateromarginal teeth gradually narrower, smaller, and rather more pointed cusp. Some outermost teeth with a small and pointed cusp at inner side.

External appearance (Figs 3A, 5A). Living animal with reticulated skin and pale freshy-grey body. Five mantle extensions present, same colour as body. Sole divided into three parts longitudinally. Caudal foss (cf) and caudal horn (ch) present with similar colour to body.

Etymology.

The specific epithet is the Latin word fasciola meaning band or stripe. It refers to the presence of a brownish peripheral band, which characterises this species.

Distribution.

Burmochlamys fasciola sp. nov. is known from two limestone areas in the south of the Salween River basin (Fig. 1). The Bardai Mountain (Fig. 2A) and Kyankaw Mountain are surrounded by paddy fields that are temporarily flooded during the monsoon season. In Kyankaw Mountain, this new species is sympatric with the limestone karst-restricted land snail species, Sophina salweenica .

Remarks.

The distinguishing characters of B. fasciola sp. nov. is a milky-white shell with a narrow yellowish brown peripheral band and rather elongated radular teeth. Whereas the other Burmochlamys species have a pale to dark brownish shell without any band and the radular teeth have a broad spatulate shape (see Table 2).

*Information from Blanford and Godwin-Austen (1908).