( 22 ) 



DIVISION VII. AMMONACEjE. 



GENERA. 



1. Ammonites. Brug. 



Septa of the chambers A siphon, generally Abounding in the Se- 

 undulated at the mar- marginal. ' condary Mountains, 



gins. (1) from the size of a pin to 



that of a coach-wheel. 



a. Ammonites, Lam. All the turns visible. PI. 1, fig. 15. 



b. Orbulites, Lam. The last turn enveloping all the others. PI. 3, fig. 11, 12. 



(1) According to Spallanzani, there are vast beds of Ammonites in the environs 

 of Never s. They have been found in England, in all the formations from the 1st 

 or alluvium, to the 8th or first sand stone, inclusive. 



DIVISION VIII. NAUTILACEiE. 



GENERA. 



1. Nautilus. , 



The last turns of the Septa numerous, sim- V. Animal, p. 54. 



spire not only touch but pie, transverse, siphun- 



envelope the preceding, ciliated. 

 PI. 2, lig. 2, 3,4. 



a Nautiutes. (1) 



§ Microscopic. 



a Lenticulina, (2) Lam. The last turn, as in the existing species, pi. 2, fig. 17. 

 n . . i in the middle of the septa. 

 Une siphon . . J iGwards ihc ante rior edge. 



{towards the edge, 

 scattered, 

 ranged in a longitudinal line, 

 ranged in a transversal line. 



...... * • , f longitudinal. 



A skt, instead of a siphon . . J im % vcrsaL 



£ Rolalites. (3) Lam. The mouth placed more on one side than the other, 



or entirely on one side, pi. 2, fig. 13. 



y Discorbites. (3) Lam. All the turns visible, pi. 1, fig. 5. 



$ ^ The last turn very large in comparison with the 



rest of the spire. 



§§ Large or moderate. 



a. Anguiites. (4) Montf. One siphon. 

 (6 Bisiphites. Montf. Two siphons, 

 y Planulites. Lam. Siphon towards the edge. 



<T Ellipsolites.(5) Montf. Spire elliptic, pi. 3, fig. 15. 

 » Amaltes. Montf. Siphon in the middle. 



(1) Foss. in the London Clay ; Crag Marl ; Chalk Marl; Green Sand ; Under 

 Oolite ; Blue Lias; Derbyshire Peak or Mountain Lime Stone. 



(2) Foss. atSenlis; Soisson ; Grignon ; Meudon. Lamarck possesses Lenticu- 

 lina: in the recent state which were found in 125 fathoms off Teneriffe. 



(3) Foss. Grignon. 



(4) Foss. Grignon. Defiance has received specimens in the recent state from 

 New- Holland and the Red- Sea. 



(5) Foss. in the Derbyshire Peak Lime Stone. 



