72 
Syn. Pleurotomaria conica, Phill. Geol. Yorks. 228. 
pi. 15 .f. 22. Morris, Catal . 158. 
T. he band around the margin of this elegant shell is nar- 
row and so hollow as to appear like two sharp ridges or 
keels, and the furrow below produces almost a third ridge, 
particularly in some specimens. The striae above the band 
are numerous, elevated, slightly curved and very oblique; 
the striae below the band are equally numerous and ele- 
gantly curved. 
P. striata {Helix, Min. Con. tab. 171.) has slightly con- 
vex whorls, more distant, less oblique and stronger striae, 
a wider and flatter band, and shorter spire, otherwise it 
bears a strong resemblance : they both are liable to be va- 
riegated with dark brown. 
Found in the carboniferous limestone of Bolland. 
PLEUROTOMARIA tumida. 
TAB. DCXL — fig. 5. 
Spec. Char. Depressed, nearly smooth ; whorls 
few, rounded, convex above with a slight canal 
near the suture, very convex beneath ; umbi- 
licus small with a sharp edge ; band mode- 
rately broad, sunk; aperture transversely ovate. 
Syn. P. tumida, Phill. Geol. Yorks. 226. pi. 15. 
f. 3. Morris, Catal. 159. 
Remarkable for the rapid increase of the whorls and the 
slight depression in them near the suture. The specimen 
has lost much of the shell, but what remains is of a very 
dark colour except a white stripe below the band. Sent 
to me from Bolland by Mr. Gilbertson. 
