4-M 
THE GEOLOGIST. 
its extcnial foi'm it is not unlike Terehratnlina suhradiata, but it does 
not, in any example I have seen, attain one-tenth the size of 
that species. It is also more circular, less convex, and has a more 
pronounced sinus in the ventral valve than that shell.* 
The T. radiata appears to have continued upwards from the Inferior 
Oolite, as I am unable to separate fi-om it some specimens I have 
obtained from Dundiy, near Bristol, the only distiiiction being that 
the latter assume a more elongated form, which is to be observed by 
comparing pi. xiii., fig. 14 (from Dundiy) with figs. 11, 12 (from 
Hampton Clilfs). 
Zellania. Moore : 1854. 
Three species of this genus were described by me in the Transactions 
of the Somersetshire Natural History Society, for 1854; one being 
from the Upper Lias, the other from the Inferior Oolite of Dundry. 
To these I have to add another fi-om Dundry, and a fifth species from 
the Oolite of Hampton Cliffs. The genus also occurs in the Coral 
Rag of Lyneham, Wilts. Its range is therefore shown to extend 
from the Upper Lias to the uppermost beds of the Oolite. 
Zellania globata. Moore. PI. xiii., figs. 15-17. 
Shell very small, globose ; valves moderately convex, rounded at 
sides and front ; exterior surface smooth ; beak slightly projecting ; 
foramen encroaching on both valves, rounded. 
OJjs. — I have five examples of this shell from the Oolite of Hamp- 
ton. The intei'ior of the dorsal valve possesses a well defined circular 
ridge, entirely encircling the inner portion of the shell. In this 
species I have been unable to observe any trace of a central septum, 
which in those previously figured is well defined. The examples 
that occur in the Coral Rag, at Lyneham, are of the^ same species, 
and are equally rare. 
Zellania oolxtica. Moore. PI. xiii., figs. 18-20. 
Shell small, triangular, rather longer than wide ; front rounded ; 
valves tapering to the beak, smooth, distinctly puntuatc, thickest at 
the umbo ; sides thick, flattened ; hinge-line very short ; foramen 
rounded. 
This species is found with the Z. Davidson!, and Z. Labouclieroi. 
It is a thicker and more triangular shell than the former, and is de- 
void of the striaa noticed on that shell. In its triangular and less 
symmetrical form it is to be distinguished from Z. Lahouclierci ; and 
it also wants the concentric lines on the valves characteristic of that 
species. The shell structure of the genus is shown by the Z. ooUtica 
to be distinctly punctuate. 
* In all the examples that have come tinder my notice, the crural processes, 
which are usually joined in this genus, are disconnected. 
