AMONITES monife. 
TAB. CXVIL 
Spec. Char. Sub-umbilicate, with tubercular radii ; 
inner whorls exposed ; tubercles hollow, in the 
interior deep, externally obsolete on the mar- 
gin ; external surface divergingly striated ; 
aperture transversely ovate. 
In the cast the radii are composed of tubercles gradually 
rising higher and becoming elongated towards the front, 
where the last one is bifid; this and several others are not 
to be seen on the outside, because the shell is so thick 
between them as to make the surface level. The inner sur- 
face is smooth ; the front rather concave, finely striated 
externally. Aperture about one-third the diameter of the 
shell in length, and nearly twice as wide. Occasionally 
we see the siphuncle just within the front. 
I am favoured with this, and other curious productions 
of the green sand at 8 and gate, near Folkstone, by a dis- 
cerning friend, whose zeal for scientific research could not 
resist attention, even to the often refused rejectamenta of 
former animation, preserved, I am apt to think, as monu- 
ments of the most highly instructive nature, regarding the 
lapse of ages ; while they often afford splendid examples 
of beauty increased by premature decay. 
This Ammonite in many ways baffles description, in 
being so various according to its state of preservation; 
the shell is thick originally, and rather laminated; its 
surface decaying may give much variety as to the protu- 
berances, while it occasionally becomes nacreous with ail 
indescribable lustre; and often most so when the last 
