"A fairly large, partially cavate, gonyaulacacean dinoflagellate
cyst species. The smooth endocyst is approximately square in outline and has
a distinct, distally rounded and closed apical projection. The pericyst, which
is also smooth, is in contact with the endocyst only on the dorsal surface and
is produced into a well-developed, straight or concave-sided, open apical horn.
Paratabulation of the formula 4', la.s., 6, ?c, 5''', 1p., 1p.v., 1'''' is
marked on the pericoel surface by low crests which are distally irregularly
denticulate. An irregular hole is observed in the ventral pericoel, presumably
marking the parasulcus. An archeopyle is formed by detachment of paraplate 3''."
- From Duxbury (1983, p. 47).