CEPHALOPODA. 



199 



11. HeteropJiylU, 



12. Ligati, 



P. JBacJc round, convex, 



L. ool. A. heterophyllus (Fig. 41). 

 cret. A. planulatus (PL III., Fig. 3). 



Fig. 63. Ammonites coronatus* 



13. Annulati, ool. A. annulatus, biplex, giganteus. 



14. Coronati, ool. A. coronatus (Fig. 63), sublaevis. 



15. Fimhriati, ooL A. fimbriatus, lineatus, hircinus. 



16. Cassiani, 36 species of very variable form, and remarkable 

 for tbe number and complexity of their lobes. Trias, Austrian 

 Alps. 



Fig. 64. t 



Examples, A. Maximiliani (Fig. 64), A. Metternicbii. 



Ceioceeas, Leveille. 



Etymology, krios, a ram, and ceras, a horn. 

 Synonym, Tropseum, Sby. 



Example, 0. cristatum, D'Orbigny (PI. III., Fig. 8). 

 >S7ieZZ discoidal ; whorls separate. 



Distribution, 13 species. Neocomian — Upper greensand. 

 Britain, France. 



* Fig. 63. Profile of Ammonites 'coronahis (Brug.). (Reduced | from D'Orbigny.) 

 Kelloway Eock, France, d I, dorsal lobe ; s s, dorsal saddles ; I' I' lateral lobes ; s' s', 

 laferal saddles ; accessory and ventral lobes. The number of accessory lobes increases 

 with age. 



t Fig. 64. Am. Maximiliani, Klipstein. {= A. bicarinatus, Miinst.) Trias, Hallstadt 

 (copied from Quenstedt). A, profile, showing the numerous lobes and saddles; B, 

 suture of one side ; v, dorsal saddle. 



