1971 Intoceratidae Kuzina: 39.

A:   Conch form discoidal, involute, with narrow umbilicus;
ventral side may be oxycone.
B:   Ornamentation consisting of distinct growth lines, rarely
with weak lirae in ventrolateral area.
G:   Ventral portion of suture primitive; ventral lobe with
diverging sides, at its base very narrow, bifid or with small
median lobe. First lateral saddle broadly rounded and wide.
Adventitious lobe rounded, in some genera rather small.

Fig. TAX3773 A: Aquilonites angustilobatum, B: Intoceras glabrum,
C: Quasiintoceras bogoslovskyi, D: Oxintoceras thaumastum
(sutures, from Kuzina, 1980).