CEPHALOPODA. 



93 



GONIATITES, De Haan. 



Etym., gonia, angles (should be written gonialites ?). 

 Syn., aganides, Montf. 



Examples, G. Henslowi, pi. III., fig. 1., G. sphericus, fig. 53, and 39. 

 Shell, discoidal ; sutures lobed ; siphuncle dorsal, 

 Distr. 150 sp. Devonian Trias, Europe. 



BACTRITES, Sandberger (= stenoceras, D'Orb ?). 

 Shell, straight ; sutures lobed. Type, B. subconicus, Sbger. 

 Distr., 2 sp. Devonian Germany. 



ifOhA Ay^ y 1 ^ hnS **& 



Fig. 54.* 



CEEATITES, De Haan. 

 Type, C. nodosus, pi. III., fig. 2. 



Shell, discoidal ; sutures lobed, the lobes crenulated. Fig. 54. 

 Distr., muschelkalk, 8 sp. Germany, France, Russia, Siberia. 

 Salt-marls (Keuper). 17 sp. S. Cassian, Tyrol. 



M. D'Orbigny describes 5 shells from the gault and U. greensand as 

 ceratites; but many ammonites have equally simple sutures, when young. 



Fig. 55. t 

 AMMONITES, Bruguiere. 



Etym,, ammon, a name of Jupiter, worshipped in Libya under the form 

 of a ram. The ammonite is the cornu ammonis of old authors. 



* Fig. 54. Suture of ceratites nodosus (Brug). The arrow in the dorsal lobe 

 points towards the aperture. 



t Fig. 55. Ammonites rostratus, SLy. From the U. green-sand of Devizes, in the 

 cabinet of W. Cunnington, Esq. b, front view of one of its partitions. 



