Shell gelatinous, cartilaginous, transparent, in shape of a reversed pyramid or lanceolate truncated, only open at the summit.
Cleodora pyramidata.
Cleodora caudata.
C. pyramidata. The pyramidal Cleodora.
Like a pyramid, triangular, thin, transparent; aperture obliquely truncated.
4. Limacina. One species.
Shell papyraceous, very fragile, planorbis form, sub-carinated, involuted rather obliquely, in such a manner as to be deeply and largely umbilicated on one side, and the spine slightly projecting and pointed on the other; aperture large, entire.
L. helicialis. The Helix-like Limacina.
Thin, fragile, spiral; the volutions united in a discoid form.