DESCRIPTION OF THE FOSSILS. 
223 
donta,) mesial ribs numerous ; margin squared. I have a very singular variety from 
Kirby Lonsdale with much elevated biplicate mesial fold, and projecting quadriplicate 
sides, (avicularia.) 
T. ventilabrum ? Ph. PI. XII. fig. 36, 38, 39. Bolland, &c. 
Whether this be distinct from T. sulcirotris, I am not sure. It resembles an 
oolitic species, a. no mesial elevation, fig. 36. /3. ribs rounded and vanishing toward 
the margin. 
T. excavata. Ph. PI. XII. fig. 24. Isle of Man. 
Oblong, flattened, with steep edges, excavated on the sides near the beak, plaits very 
deep and angular, a. mesial plaits three ; lateral two ; /3. mesial plaits four. 
T. radialis. Ph. PL XII. fig. 40, 41. Bolland. 
Orbicular, no mesial fold ; ridges equal, rounded, radiating. 
T. proava. Ph. PL XII. fig. 37- Bolland. 
Oblong, beak produced, radiations obtuse, mesial fold square. Strongly allied to the 
oolitic species T. obsoleta, T. socialis, &c. 
T. antiquata. Ph. PI. XI. fig. 20. Bolland. 
A very singular small brachiopodous shell (perhaps producta) of an oval figure ; 
lower valve convex, upper plane with two diverging convexities, hinge line straight. 
GASTEROPODA. 
Patella scutiformis. Ph. PI. XIV. fig. 1 . Bolland. 
Depressed, scutiform, elliptical, smooth, vertex acute, inflexed, nearly marginal ; 
very fine radiating stria:. 
P. sinuosa. Ph. PI. XIV. fig. 2. Bolland. 
Depressed, smooth, sinuoso-oval; vertex irregular, prominent, near to the narrow 
end. 
P. mucronata. Ph. PL XIV. fig. 3. Bolland. 
Conical, smooth, depressed ; apex mucronate, acute, central ; limb orbicular, base 
not plane. 
P. curvata. Ph. XIV. fig. 4. Bolland. 
Curvato-conical, smooth ; base plane ; limb orbicular ; apex acute, central. 
P. retrorsa. Ph. PL XIV. fig. 5. Bolland. 
Depressed-conical, with many broad radiating sulci ; limb elliptical, undulated ; 
apex acute, retroflexed. 
P. lateralis. Ph. PI. XIV. fig. 6. Bolland. 
Conical, smooth, a lateral sulcus, and posterior radiations ; apex acute, 
Metoptoma. — New genus. Patelliforra, face under the apex truncate. 
