138 
perhaps even the form of the tube itself, are liable to 
variation ; these are still further difficulties. 
Hamites have been found in the Clay at Folkstone, as 
most of the species here figured ; in the Chalk at Ilamsey 
in Sussex, resembling H. intermedins; and also by Miss 
Benett, in the Chalk at Horton. 
HAMITES tenuis. 
TAB. LXL —Fig. 1. 
Spec. Char. Slender, depressed, undulations obtuse, 
slightly waved, disappearing on the back of 
the limbs. 
The compressed shape of this would give the aperture an 
oval form about half as long again as wide. The undula- 
tions are irregular, some reaching nearly to the back, others 
only half way. The fragment I have figured is straight, 
and tapers more rapidly than others of the Genus. 
I am indebted to the indefatigable James Gibbs for this 
and most of the specimens figured in this and the following 
plate. They were picked up by him in the Clay of the 
neighbourhood of Folkstone, among Ammonites and various 
other Fossils. 
HAMITES rotundus. 
TAB. LXI. — Figs . 2 and 3 , 
Spec. Char. Aperture round, undulations obtuse^ 
annular, numerous ; the curve of the shell very 
gradual. 
The regularity of the undulations and roundness of th# 
shell, are the distinguishing marks of this species. Fig. 2 
