Microcystis dyakana (Godwin-Austen, 1891)
“This might very easily be mistaken for Microcystis tersa but for its larger size and fewer whorls, the form of the apex of the shell when viewed from the front being also very different. The animal is of a pale ruddy brown colour with large black patches and spottings. The right shell-lobe very ample, triangular in form; the left shell-lobe also large as well as the neck-lobes. The radula was not seen, this part had been destroyed before it was placed in spirit. The generative organs were also not perfect.” (Godwin-Austen, 1891)
“Three specimens from Lombock agree in every respect, excepting size, with Bornean examples. The largest shell, which may not, however, be adult, is only 7 mm. in its greater diameter.” (E. A. Smith, 1899)
Godwin-Austen (1891) original descriptions on Microcystis dyakana – “Shell globose, thin, semi-transparent, very narrowly perforate, almost imperforate; sculpture, under high lens very minute, somewhat wavy spiral striation, to the naked eye smooth and glassy; colour pale dull ochraceous; spire moderately high; apex blunt suture adpressed, shallow; whorls 4, convex, rather rapidly increasing; aperture semi-ovate; peristome sharply edged, reflected at the columellar margin, which is oblique, not thickened.”
Microcystis dyakana – “Size: maj. diam. 8.7, min, 7.7; alt. axis 4.5 millim.” (Godwin-Austen, 1891)
Type locality – “Busan Hills” leg. A. Everett (Godwin-Austen, 1891)
Other localities – ”Lombock, 1,500 feet”leg. A. Everett (E. A. Smith, 1899)