Oophana acuti carinata van Benthem Jutting, 1961
“The new species is related to Oophana hanleyana (Stoliczka), O. mirifica (Moellendorff), O. balingensis (Tomlin) and O. atopospira v. B. Jutting. From O. hanleyana it differs in the greater size (max, diam. O. hanleyana 7 ½ mm, acuti-carinata 10-12 mm.) and in the absence of ribs on the base of the whorls. From O. mirifica it differ in the greater size (max. diam. O. mirifica 9 mm., O. acuti-carinata 10-12 mm.), in the less spout-shaped aperture, in the absence of a bifurcation at the exterior point of attachment of the parietal lamella and in the presence of teeth at the free peristome margin. From O. balingensis it differs in the narrower umbilicus, the sharply pinched carination of the overhanging part of the fourth whorl, and in the presence of teeth at the free margin of the peristome. From O. atopospira it differs in the greater size (max. diam. O. atopospira 9-10 mm., O. acuti-carinata 10-12 mm.), in the less spout-shaped aperture, the absence of the bifurcation at the exterior point of attachment of the parietal lamella and the sharper and more pinched carination of the overhanging part of the last whorl.” (Benthem-Jutting, 1961)
Benthem-Jutting (1961) original descriptions on Oophana (Haploptychius) acuti-carinata – “Shell depressed-conical, glassy-white, shining and transparent. Upper surface transversely ribbed with delicate, curved ribs, about 6 to the mm on the last whorl. Towards the base these ribs fade away. Whorls 6, first 2 ½ whorls smooth. The spire is regular for about 4 whorls. In the fifth, however, the axis of the shell is pressed obliquely to the side, so that the previous whorl which is acutely carinated at the periphery (more acute and more pinched than in Oophana atopospira), projects sideways. After that the carination disappears again. Only on the last ¼ part of the last whorl two new angulations originate, a larger one at the periphery and a smaller one between the periphery and the umbilicus. Both are directed spirally and both are more evenly rounded (not sharp or pinched) than the above-mentioned carination. The side of the shell facing the umbilicus is distantly ribbed. There is no spiral striation. Spire low-conical, base rounded. Umbilicus wide and eccentric, but not so wide as in O. balingensis (Tomlin) and O. atopospira v. B. Jutting. Aperture almost rectangular, with rounded angles, not so spout-shaped as in O. mirifica (Moellendorff) and O. atopospira. Its position is very oblique, both in vertical and horizontal directions. Peristome not continuous. Free margin reflexed and thickened and horizontal directions. Peristome not continuous. Free margin reflexed and thickened. Parietal lamella strong, undulating, entering the aperture for about 4 mm. Exterior point of attachment of the lamella somewhat thickened, but never bifid as in O. atopospira and O. mirifica. Upper and outer margins of aperture each with a short, conical tooth. Lower margin with a broad, indistinctly defined tooth which is hardly more than a local thickening of the peristome.”
Oophana (Haploptychius) acuti-carinata – “Dimensions; Greatest diam. 10.5-12.5, height 4.25-5.25, Length of aperture 5.0-5.5 mm.” (Benthem-Jutting, 1961)
Type locality – “Gunong Sinyum, Pahang” leg. Benthem-Jutting/June 1954 (Benthem-Jutting, 1961)