240 CATALOGUE OF THE FOSSILS OF THE PERMIAN SYSTEM 
ribs in some specimens are very distinct, with a deepish furrow 
and a smaller rib between them ; in others the ribs are indistinct 
and the surface is covered with spiral planes. The ribs are 
smaller and more numerous on the under part of the whorls. 
The striz of growth are generally very strong. The 7’. minuta 
appears to be only the young of this species. 
2. L. TUNSTALLENSIS, 7. s. 
Shell small, conical ; spire elongated, composed of 4 or 5 
gradually enlarged whorls, which are very round and 
finely ribbed or sulcated ; aperture round ; prilar-lip 
rather flattened. 
In Magnesian-limestone ; rather rare. Tunstall-hill. 
Though found with the former species, it is easily distinguished 
from it by the gradual enlargement and roundness of the whorls, 
the fineness of the ribs, the comparative length of the spire, and 
the absence of a slit behind the pillar-lip. It is also less com- 
mon and much smaller. Specimens sometimes occur which are 
nearly smooth. 
3. L. minima, Brown. 
Natica minima, Brown, Manch. Geol. Tr.i., pl. 6, f. 22—24. 
In Magnesian-limestone ; not common. ‘Tunstall, Silksworth. 
This smooth species has the pillar-lip flattened with an 
angulated base, but so slight, as not to destroy the orbicular form 
of the mouth ; when not worn, it is covered with fine strie of 
growth. 
With the former species this very much resembles some of the 
recent Littorinew. The outer-lip of some of the specimens has 
been fractured and again repaired similarly to what may often 
be observed in many littoral species. 
10. TURRITELLA, Lamarck. 
1. T. Paruurpsit, 2. s. 
Melania » Phill., Geol. Trans. 2nd ser., iii., p. 118. 
Shell elongated, narrow, slightly tapering, turretted,; spire 
with 12 or more rounded whorls, which are rather conveu 
and slightly flattened behind, suturedeep,; piltar-lip slightly 
angulated in front; aperture sub-orbicular. 
