GOMPHOCEEATIDJE. 
211 
Family GOMPHOCERATID^. 
[EQUILOBATES \] 
Genus GOMPHOCERAS9 J. de Carle Sowerby^, emend. Hyatt 
{JPhragmoceras, J. de 0. Sowerby, 1839 ^ (partim) ; Dimorion, Barrande, 
1867 ^ ; Dimeres, Barrande, 1867 ®.) 
Gen. Char. The shell ranges from an approximately straight 
form, in relation to the main axis, through varying degrees of cur- 
^ Hyatt (Proc. Boston Soc. Nat. Hist. vol. xxii. 1883, p. 277) has divided the 
Gomphocemtidce into two groups, viz. : — Equilobates and Inequilobates ; in 
the former the dorsal orifice of the aperture has a median saddle, and there- 
fore an equal number of lateral lobes, while in the latter, instead of the median 
saddle, there is an unpaired dorsal sinus. The accompanying figures will make 
this clear ; — 
2 Murchison’s Sil. Syst. pt. ii. 1839, p. 620. 
The following names have been applied by various authors to fossils belong- 
ing to the genera Go^nphocems and Vhragmoceras, as originally constituted : — 
Orthocera, Sowerby (Min. Conch, vol. hi. 1821, p. 85, tab. ccxlvii.); Campu- 
lites, Deshayes (partim), (Encyclop. Methodique, tom. iii. 1832, p. 675) ; Nau- 
tilus'i, Hisinger (Lethsea Svecica, 1837, p. 27, pi. vii. f. 1); OrtTioceratites, 
Munster (Beitriige zur Petrefactenkunde, 1840, Heft iii. p. 103, Taf. xx. f. 10) ; 
Bolhoceras, Apioceras, Fischer (Bull. Soc. Imp. des Nat. de Moscou, tom. xvii. 
no. 3, p. 779) ; Orthoceratites Injiati, Quenstedt (Petrefactenkunde Deutsch- 
lands, 1849, Abth. i. Band i. Die Oeph. p. 45) ; Sycoceras, Pictet (partim) 
(Traite de Paleont. 2nd ed. 1854, tom. ii. p. 645). 
® Proc. Boston Soc. Nat. Hist. vol. xxii. 1883, p. 277. 
Murchison’s Sil. Syst. pt. ii. 1839, p. 621. 
5 Syst. Sil. de la Boheme, vol. ii. pt. i. p. 265. 
6 Ibid. p. 203. 
Fig. 33. 
Equilobates type. 
m. Median saddle. 
Inequilobates type. 
cl. Dorsal sinus. 
p2 
