Hypselostoma megaphonum van Benthem Jutting, 1950  

Benthem-Jutting (1949) original descriptions on Hypselostoma megaphonum – “Shell consisting of a moderately conical spire and a free, trumpet-shaped last whorl. Dark reddish-brown, somewhat more yellowish-brown towards the aperture. First 1½ whorls smooth, polished. The others regularly striated with oblique growth lines. There is no spiral striation. Not transparent. Whorls about 5, of which 4¾ are regularly coiled and adnate, and about ¼ free and projecting. Whorls evenly rounded, suture deep. Last whorl somewhat inflated before the free part begins. The free part itself is narrower, but extends towards the aperture. On the last whorl a peripheral keel makes its appearance at the end of the fourth whorl. The keel continues on the side of the free part, fading somewhat towards the aperture. Umbilicus almost entirely hidden by the inflated portion of the last whorl. Aperture more or less vertical, widened, trumpet-shaped. Peristome continuous, somewhat thickened and expanded. The mouth contains 4 rather strong teeth, placed cross-wise: one parieto-angular, one upper and one lower palatal, and one columellar.”