Subulina octona (Bruguiere, 1789)
“This species, for which others have frequently been mistaken, may be distinguished by its delicate shining surface and very transparent texture; the sutures of the spire are also peculiarly impressed, giving a globose form to the whorls, It has a very wide range of habitation, and is composed sometimes of eight, sometimes of ten whorls.” (Reeve, 1849)
“Under stones, grass, moss and other ground objects, chiefly in the lowlands. Highest record 700 m.” (Benthem-Jutting, 1952)
Reeve (1849) descriptions on Achatina octona – “Shell subulately turreted, sutures impressed, whorls eight to ten in number, somewhat rounded, very minutely striated, shining, columella arched, twisted, but little truncated, aperture very small; transparent waxen, pale strawcolour.”
Ghosh (1929) original descriptions on Opeas doveri – “Shell elongated turretted, stenogyroid, thin; translucent and pale. Spire gradually tapering. Whorls 8½ to 9, convex, faintly striated, except the first two, which arc more or less smooth; the third and fourth whorls somewhat suddenly smaller than the next and thus distinct from them; the seventh and eight whorls very nearly equal to each other; others gradually enlarging. Sutures between the whorls impressed. Apex blunt. Aperture irregularly ovoid; outer border convex, the convexity being more marked posteriorly; columellar border flat or faintly concave in front and with a rounded notch behind. Columella straight and vertical. There is no jaw. The entire width of the radula could not be dissected out. The rows of teeth are very nearly transverse. The median tooth is minute, narrow and is much smaller than the lateral ones; there are no lateral cusps, the only median cusp is thinner towards the free end than towards the basal portion. The lateral teeth are rather wide. The median cusps are elongately ovate, the free end being triangular. The marginal differs from the laterals in that they have n longer basal portion and the portion occupied by the cusps is short. In spite of the fact that. the entire width of the radula could not be taken out, it is probable that the radula is comparatively narrow. There seem to be nine lateral teeth on each side. Altogether eighteen teeth were found on each side of the median tooth. In several specimens examined, there were five oblately spheroidal eggs in the female portion of the common genital duct. A minute pigment spot was noticed in the eyes of some specimens, but not in others.”
Benthem-Jutting (1952) descriptions on Subulina octona – “Shell high-turreted, with nnumerous whorls. Glassy yellowish-corneous, sometimes a little greenish. Highly polished and transparent. With fine vertical striation; spiral striae very weak. Whorls 9 to 10, regularly increasing in size. Well rounded, suture distinct, not marginated, but somewhat crenulated, especially in the older whorls. Last whorl about two-fifths of the entire shell-length. Top obtuse, base rounded. Imperforate, even in young animals. Aperture oblique, almost oval, pointed above and below. Peristome not continuous, sharp, not thickened or reflected. The columella is truncated at the lower extremity.”
Opeas doveri – “Greatest length 18-20 mm.; greatest breadth 3.8-4 mill.; greatest length of aperture 3-3.1 mm.; greatest breadth of aperture 2 mm.” (Ghosh, 1929); Subulina octona – “Dimensions: height 19 to 20 mm, width 4 ½ to 5 mm, height of aperture 3 ½ to 4 ½ mm.” (Benthem-Jutting, 1952)
Type locality – Opeas doveri “Batu Caves (Dark Cave)” (Ghosh, 1929)
Other localities - “Kelantan, Malay Peninsula” leg. J. Waterstradt (Sykes, 1902); “Mittel-Sumatra: am Singkarak-See” (Rensch, 1934); “W.-Java: Buitenzorg” (Rensch, 1934); “West Java: Antjol, near Djakarta, and Tandjong Priok, sea-level; Djakarta, 15 m” (Benthem-Jutting, 1952); “West Java: Bogor, Botanical Garden, 250 m” (Benthem-Jutting, 1952); “West Java: Sukabumi, 700 m” (Benthem-Jutting, 1952); “West Java: Tjiandjur, 470 m” (Benthem-Jutting, 1952); “West Java: Bandung, 700 m” (Benthem-Jutting, 1952); “West Java: Garut, 700 m” (Benthem-Jutting, 1952); “West Java: Tjisompet, 450 m” (Benthem-Jutting, 1952); “Central Java: Rembang, sea-level” (Benthem-Jutting, 1952); “East Java: Botanical Garden, Surabaja, sea-level” (Benthem-Jutting, 1952); “East Java: Malang, 500 m” (Benthem-Jutting, 1952);
Distributions – “von Amerika aus in viele Tropenländer verschleppt, Auf dem Sundabongen nachgewiesen für Sumatra, Java und Bali” (Rensch, 1934); “Subulina octona is a tropical cosmopolite. It is difficult to say in which country it originated. In the Malay Archipelago it has been recorded since 1890 (Boettger, i.c.) and is now present in almost all islands. Introduction into hothouses in Europe and the U.S. (Meeuse, 1949) has already been mentioned.” (Benthem-Jutting, 1952)