The shell is markedly tumid, with a radial sculpture on the first whorl. – Above: young specimen collected from 1000m deep, Capo Teulada, Cagliari, S. Sardinia. 1mm. The radial striae appear more or less at the first half of the first whorl, and disappear once this whorl is completed; then, the shell continues to grow, without that sculpture, during a minimum of half a whorl more. These radials are minutely undulating.