1938  Syngastrioceras Librovitch: 72, 81, 103.
     1960  Syngastrioceras.- Ruzhentsev: 212.
     1962  Syngastrioceras.- Osnovy: 376.
     1968  Syngastrioceras.- McCaleb: 47.
     1969  Syngastrioceras.- Gordon: A5.
     1971  Syngastrioceras.- Ruzhentsev & Bogoslovskaya: 294,
       ----  Pseudoglaphyrites Ruzhentsev & Bogoslovskaya: 292.
     1975  Syngastrioceras.- Nassichuk: 84,
       ----  Neogastrioceras.- Nassichuk: 95.
     1978  Syngastrioceras.-Yang: 163.
     1982  Syngastrioceras.-Nishida & Kyuma: 27.
     2000  Syngastrioceras.-Titus: 41.

Type species: Gastrioceras orientale Yin, 1935, p.19 [OD].

[= Pseudoglaphyrites RUZHENTSEV & BOGOSLOVSKAIA, 1971, p.292, type P. shokalensis, p. 293, OD (subj.), for discussion see NASSICHUK, 1975, p.95; = Neogastrioceras NASSICHUK, 1975, p.95, type N. arcticum, p.66, OD (subj.)].

A:   Conch form pachycone to globular, umbilicus moderately wide to narrow.
D:   Constrictions may be present on internal mold.
G:   Suture-line like Glaphyrites, but first lateral saddle subacute to acute on adult stages. Median saddle at least half the height of entire ventral lobe.

[Transitional to Eosyngastrioceras and Glaphyrites. Pseudoglaphyrites and Neogastrioceras differ slightly in the suture-line: their ventral prongs are wider, the first lateral saddle in Pseudoglaphyrites is more acute, in Neogastrioceras narrower].

Fig. see TAX6017 A: S. globosum (suture), TAX6017 B: S. sp. (cross-section).
    
[Ruzhentsev & Bogoslovskaia, 1971, p. 294:  Syngastrioceras:
Conch from subsphericone or subcadicone to sphaericone.  Whorls more or less involute.  Umbilicus of varying size.  Shell surface is covered by weak lamella, which form a ventral salient of varying size in young individuals, weakening and disappearing with age.  3-4 Constrictions per whorl are only sharp on the steinkern and disappear with age.  Ventral lobe not very wide (lobe width /height from 0.70 to 0.85), pressed together at the top and has lanceoulate prongs.  Lateral lobe is cupola-shaped, in young individuals clearly, and has a long prong.

[Ruzhentsev & Bogoslovskaia, 1971, p. 292:  Pseudoglaphyrites:
Large, pachycone conch.  Whorls from very to moderately involute.  Umbilicus of medium size.  Shell surface almost smooth.  Sometimes two constrictions per whorl, seemingly only on the steinkern.  They are straight, with a light declivity backwards.  The width of the ventral lobe is slightly greater than its height.  Prongs of the ventral lobe are quite wide and devided by a narrower median saddle.  Its height reaches 70-80% of the height of the whole lobe.  First outer saddle is very thin and has a tendancy to sharpness.  The umbilical lobe moves towards the umbilical seam during evolution.]

[Nassichuk. 1975, p.84: Shell varies from thickly discoisdal to subglobular. The umbilicus is typically close to 40 per cent of the conch diameter but closely approximates 10 per cent in some species. Umbilical shoulders are angular or narrowly rounded and
the the umbilical walls steep. Shell is typically smooth but some species possess faint transverse lamellae on the lateral flanks. Constrictions form a broad ventral salient during early ontogenetic stages but do not persist to full maturity.
Details of the external suture best charakterize the genus; the secondary ventral saddle is high, and the first lateral saddle is
narrow, subangular, an asymmetric. the first lateral lobe is broad, inflated medianly, and markedly attenuate.]

Titus, 2000, p.41: No ophioconic phase, wide ventral lobe  with swollen ventral prongs and a frequently constricted base. Prominent single spiral cord on each umbilical shoulder. Usually broadly prorsiradiate growth striae over the ventral region.

Fig. see TAX6017 C (suture). TAX6017a (cross-section).