PLATE XXIII. 



Fif:. 



\a, h, c. Ammonites curvatus ; from the Grey Chalk of Veutnor, Isle of Wight; in my 

 possession, p. 49. 

 l«, side view. 

 13, front view. 

 l: ^ ' 1 c, outline of a septum. 



2. Ammonites falcatus ; outline of the septum of a specimen from the Chloritic Marl of 



Ventnor, Isle of Wight; in my possession, p. 21. 

 3<7, b, c. Ammonites Salteri; from the Chalk with siliceous grains, Chardstock, 

 Somersetshire ; in the collection of J. Wiest, Esq., p. 50. 

 3fl, side view. 

 "db, front view. 

 3c, outline of a septum. 

 4«, b, c. Ammonites Ramsayanus ; from the Chalk with siliceous grains, Chardstock, 

 Somersetshire; in the collection of J. Wiest, Esq., p. 51. 

 4«, view of the left side. 

 43, view of the right side. 

 4c, front view. 



ha, b. Ammonites Salteri ; from the Chalk with siliceous grains, Chardstock, Somerset- 

 shire; in the collection of J. Wiest, Esq., p. 50. 

 5<2, side view. 

 53, front view. 



6a, 3, c. Ammonites Feraudianus; from the Grey Chalk of Ventnor, Isle of Wight; in 

 my possession, p. 52. 

 6<a;, side view. 

 63, front view. 

 6c, back view. 



la, 3. Ammonites Bravaisianus ; copied from Plate XCI, figs. 3 and 4, of D'Orbigny's 

 ' Paleontologie Fran^aise, Terrains Cretaces.' p. 52. 



8. Ammonites Bravaisianus; from the Middle Chalk of Dover; in the collection of 



of S. J. Mackie, Esq. : the specimen has been worn, and the tubercles 

 are nearly all rubbed off, p. 52. 



9. Ammonites Bravaisianus; from the Middle Chalk of Dover; in the collection of 



J. W. Flower: restored by the artist from a broken specimen, p. 52. 



10<2, 3, c. Ammonites Wiltonensis; from the Grey Chalk, near Devizes, W^iltshire; in 

 the collection of W. Cunnington, Esq., of Devizes, p. 53. 

 10(2, side view. 

 103, front view. 

 10c, outline of a septum. 



\\a, b, c, d, e. Ammonites Jukesii ; from the hard Chalk of the county of Londonderry ; 

 in the Museum of Practical Geology, p. 53. 

 \\a, side view of a fragment, with part of three whorls. 

 113, side view of the two inner whorls of 11a. 

 lie, back view of 113. 

 \\d, section of the whorls restored, 

 lie, part of the outline of a septum. 



