Oophana atopospira van Benthem Jutting, 1954
“The new species differs from the undoubtedly very closely related O. (H.) mirifica in the following points: O. (H.) atopospira is larger and has a slightly projecting apex (in mirifica the top is flat). It is not so oblique as mirifica, the overhanging part of the fourth whorl being about half as broad as in mirifica and the carination not so sharp. While our new species is ribbed on the upper side of the whorls O. (H.) mirifica is entirely smooth, only the growth lines being visible. The base of the last whorl in mirifica is flatter, even somewhat concave, an the umbilicus narrower. Along the umbilicus the terminal part of the last whorl is angular in O. (H.) mirifica, but evenly rounded in O. (H.) atopospira. The constrictions in the last whorl close to the peristome are more developed in atopospira than in mirifica. Finally the aperture of mirifica is narrower than in the new species because the upper and lower margins are closer together. O. (H.) atopospira differs still more obviously from O. (H.) hanleyana. This Burmese species is very distinctly ribbed on both upper and lower sides of the whorls, has a more elevated apex and a more overhanging part of the fourth whorl. The aperture of O. (H.) hanleyana is not spout-shaped and lacks the constrictions just behind the peristome. From O. (H.) striatula, andamanica and blanfordi the new species differs in having a spout-shaped aperture and constrictions behind the peristome. O. (H.) striatula has, moreover, costulations on the upper and lower side of the whorls and all three have a higher spire.” (Benthem-Jutting, 1954)
Benthem-Jutting (1954) original descriptions on Oophana (Haploptychius) atopospira – “Shell depressed-conical, glassy-white, shining and transparent. Upper surface transversely ribbed with delicate, curved ribs, about 9-10 to the mm on the last whorl. Towards the base these riblets fade away. Whorls 6. First 2 ½ whorls smooth. The spire is regular for about four whorls, In the fifth, however, the axis of the shell is pressed obliquely sideways, causing part of the fourth whorl to overlap the following whorls. This overhanging part is sharply keeled (although not so sharp as in O. (H.) mirifica (Moellendorff) or O. (H.) hanleyana (Stolizcka). The rest of the shell, even the last whorl, is not carinate. Before reaching the peristome the last whorl is transversely constricted, then widens again. Between this widened zone and the peristome there is another constriction, this time divided into an upper and a lower part by a short, elevated, longitudinal ridge, coinciding with the periphery. Top very little projecting, nearly flat. Base rounded. Umbilicus wide and eccentric. The basal part of the last whorl is not keeled or angular along the umbilicus. The side facing the umbilicus is distantly ribbed. Aperture narrow, spout-shaped, very oblique in vertical and horizontal directions. Entrance partly obstructed by the thickened peristome and by a well developed parietal lamella. Peristome not continuous. Margin reflected and thickened, especially at the points opposite the upper and lower constrictions mentioned above. The resulting callosities look like broad teeth. Parietal lamella strong, undulating, entring about 4 mm into the aperture. The exterior point of attachment forms a bifid or trigonal callosity. At the upper parietal corner the lamella forms a sinuous ridge joining the upper margin of the aperture.”
Oophana (Haploptychius) atopospira – “Dimensions; Height 3.7-4.25, Length of aperture 4-4.5 mm, Greatest diam. 9.0-10.25.” (Benthem-Jutting, 1954)
Type locality – “Kota Tongkat, Pahang” leg. Benthem-Jutting/1947 (Benthem-Jutting, 1954)