112 PAPERS, ETC. 
characters of this genus, which were then unknown. Its 
exterior had led me to suppose it allied to Morrisia, a genus 
first appearing in the chalk, which in form it much re- 
sembles. I have since obtained several examples, shewing 
its interior; which at once shew that it does not belong to 
to that genus; I therefore propose for it the generic name 
of Zellania. The Zellania has a large and rounded fora- 
men, which, like that possessed by Morrisia, encroaches 
on both valves; while on the other hand the interior of the 
dorsal valve shews that it has afinities with Thecideum, 
in having internal ridges and a central septum; and will 
consequently unite the Terebratulide with the Thecideid. 
The probability of the existence of a loop such as that 
possessed by the Argyope, has been suggested by Mr. 
Davidson, but although I have in several instances made 
dissections for its discovery, its existence cannot be satis- 
factorily established. 
This genus is at present represented by three species. 
It first appears in the upper lias, where one species is 
found ; becomes more abundant in the inferior oolite; and 
I have also found a single specimen in the great oolite of 
Hampton down. 
Examples:—Zel. Davidsonü; Laboucherei; Liasiana. 
ZELLANIA Davıpsoni..— Moore. —Plate 1, fig. 1—3. 
Shell small--rugose; presenting a slight tendency to 
striation; widest towards the front, and contracting slightly 
towards the foramen; foramen large and rounded, en- 
croaching on both valves—slightly produced beak; hinge 
line straight; area small; valves convex, the dorsal one but 
slightly so. Interior presents a uniformly rugose, granu- 
lated structure; dorsal valve has a wide flattened margin, 
