Above: an adult among filaments of its fishing web, pictured off the eastern coast of Florida. USNM 1450159 - Specimen Image 2. Original picture provided by K. Osborn for the Smithsonian Institution, NMNH, Invertebrate Zoology – (CCØ). Notice a chip of the shell on the top-left corner of the image.

The shell is globally conical with a slight dorsal curvature, thin, translucent, extremely fragile; its surface shows kinds of circular rings that correspond to fast radial increasing phases, separated from each other by a growth period during which the radial expansion is less important than the longitudinal.

Adults with the protoconch still present are extremely rare; usually, both extremities of the tubular shell are chipped. Above: specimen swimming off California. USNM 1615510 - Specimen Image. Original picture provided by S. Bush for the Smithsonian Institution, NMNH, Invertebrate Zoology – (CCØ).

The species « lays big eggs (average 0.3mm diam), lined up in a tube. During the laying, this tube breaks into small segments of three to six eggs. The laying occurs each end of day, and consists of about twenty eggs, representing the hundredth part of the parent’s weight. » – H. Fol: Études sur le développement des mollusques. Premier mémoire: sur le développement des Ptéropodes, Paris 1875, p.6. – The eggs in Fol, plate V fig.1.