OF THE COUNTIES OF NORTHUMBERLAND AND DURHAM. 241 
In Magnesian-limestone ; not common. Tunstall, Humbleton, 
Dalton-le-Dale. 
In the Geological Transactions this shell is indicated as a Mela- 
nia by Professor Phillips. Itis evidently a marine shell bearing a 
greater resemblance to Turritella than to any other genus we are 
acquainted with. It is dedicated to the above-named gentleman, 
who first noticed it as occurring in these rocks. 
2. TUNSTALLENSIS, 2. s. 
Melania , Geol. Trans. 2nd ser. ii, p, 118. 
Shell elongated conical; spire with 8 whorls, which are 
much rounded,, smooth ; suture deep ; aperture orbicular. 
In Magnesian-limestone ; not common. Tunstall-hill. 
The spire is shorter, and the whorls are more convex, and en- 
large more rapidly in this than in the preceding species. As it 
has not been noticed before it must have been considered iden- 
tical with the former species. 
11. CHEMNITZIA, D’Orbigny. 
We procured a fragment of a small shell from Tunstall-hill, 
which possesses more of the characters of this genus than of any 
other we are acquainted with. It has a few gradually increased 
whorls, which are very convex, and deeply fluted. The suture 
is deep, and the pillar straight. This may be the shell included 
in the tabular list in the Geology of Russia, as Loxonema rugi- 
fera. It cannot, however, be referred to that species, nor to the 
genus Loxonema, as the suture is deep, and not pressed against 
the former whorl, as in that genus. It is also destitute of strie. 
12. EULIMA, Risso. 
1. E. symmerrica, King. 
Macrocheilus symmetricus, King, Geol. Russ., p. 225. 
In Magnesian-limestone; rather rare. Tunstall, Silksworth. 
This elegant little shell is rather subulate in form. The spire 
has about eight slightly-convex whorls, which are quite smooth. 
It is sometimes nearly an inch in length, and a quarter of an 
inch in width. 
