1947  Irinoceras Ruzhentsev: 281.
     1955  Imitoceras.-Miller & Garner: 132.
     1957  Imitoceras.-Treatise: L49.
     1960  Irinoceras.-Ruzhentsev: 197.
     1960  Prionoceras (Irinoceras).-Kullmann: 70.
     1960  Imitoceras.-Vöhringer: 113, 114.
     1961  Prionoceras (Irinoceras).-Kullmann: 248.
     1962  Prionoceras (Irinoceras).-Kullmann: 73.
     1962  Irinoceras.-Osnovy: 363.
     1963  Prionoceras (Irinoceras).-Kullmann: 307.
     1971  Irinoceras.-Ruzhentsev & Bogoslovskaia: 149.
     1991  Irinoceras.-Liang & Wang: 73.
     1994  Irinoceras.-Korn: 69.
     2000  Irinoceras.-Work, Nassichuk & Richards: 32.

Type species: Irinoceras arcuatum Ruzhentsev, 1947, p.283 [OD].

A:   Conch form thick-discoidal, involute, with narrow or punctiforme umbilicus.
B:   Growth lines coarse, rectilinear, convex, with deep hyponomic sinus.
C-F: No ribs, constrictions, grooves or spiral ornamentation.
G:   Ventral lobe pouched.

[Ruzhentsev & Bogoslovskaia, 1971, p.149: Large, pachycone conch, whorls completely involute,
with a high, half elliptic cross section.  Umbilicus from very tight to closed.  Sculpture is
represented by well developed ribs forming a deep ventral sinus.  Ventral lobe is quite wide,
with sideward projections and a teat-like outgrowth at the base.  Lateral lobe has the same
width, but is longer and asymmetric, with a convex adoral side.]