220 
CONCHIFEJtA. 
Sl'ilENIA. 
nearly - straight; surface with concentric furrows, which be¬ 
come suddenly angular as they pass over the ridge and proceed 
to the hinge-line. 
The Carboniferous Limestone, Fermanagh, Ireland, and 
Loweek. 
14*. Sanguinolaria parvula. —The Small Sanguinolaria, 
pi. XC. fig. 38. 
S. parvula. Bean, Mag. Nat. Ilisfc. N. S. III. p. 59, f. 18. 
Transversely oblong oval, compressed, smooth, with a few re¬ 
mote lines of growth ; anterior side somewhat rounded ; poste¬ 
riorly more acute and sub-truncated ; beaks nearly central, and 
very obtuse; length, a quarter of an inch ; breadth, half an inch. 
The Cornbrash, Scarborough, Yorkshire. 
15. Sanguinolaria elegans.— The Elegant Sanguinolaria, 
pi. XC. fig. 28. 
/S', elegans . Phillips, Geo. York, I. pi. 12, fig. 9. 
Elliptical; anterior side a little narrowed and rounded ; 
posterior side obliquely sub-truncated; hinge-line nearly 
straight; beaks obtuse ; surface with many regular transverse 
furrows emanating from the anterior sido, and terminating 
where the diagonal sides pass from the beak to the margin, 
where it produces an angle. 
The Lias, Upper Shale, Yorkshire. 
16. Sanguinolaria elliptica. —The Elliptical Sanguino¬ 
laria, pi. XC. fig. 18. 
elliptica . Phillips, Pal. Foss. p. 34, pi. 17. fig. 53. 
Nearly elliptical and equilateral; hinge-line almost straight; 
the sides rounded; beaks obtuse; surface concentrically striated. 
The Devonian Rocks, Combe, near Ashburton, and Yealm 
Bridge, near Launceston. 
17. Sanguinolaria gibbosa. —The Gibbous Sanguinolaria, 
pi. XC'. fig. 29. 
/S', gibbosa. Sowerby, Y. p. 92, pi. 54-8, fig. 3. 
Much elongated transversely; gibbose, smooth ; sides 
slightly gaping and rounded ; beaks obtuse, situated near the 
anterior side ; surface smooth. 
The Carboniferous Limestone, Ireland. 
18. Sanguinolaria sulcata. —The Furrowed Sanguino¬ 
laria, pi. XC. fig. 41. 
/S', sulcata . Phillips, II. p. 209, pi. 5, fig. 5. 
Transversely elongated; anteriorly short and narrowed ; 
posteriorly lengthened, and somewhat expanded ; beaks obtuse, 
situate near the anterior side ; hinge-liue a little curved and 
hollow ; surface transversely furrowed, which become broad at 
the posterior side ; a few obsolete, longitudinal stria*. 
The Carboniferous Limestone, Otterburn and Kendal. 
Tribe II.—LITIIOPIIAGI. 
Boring shells, destitute of accessory pieces, and more or less 
gaping at their anterior side; ligament of the valves external. 
Genus XLVL—PETRICOLA.— Lamarck. 
Shell equivalve, inequilateral, transverse, for the most part 
rather triangular ; but some species are transversely elongated, 
and others sub-quadrate; posterior side rounded ; anterior 
side somewhat produced, more or less attenuated, and gene¬ 
rally gaping; each valve provided with two cardinal teeth, 
which, in some instances, are curved and acute, especially the 
posterior tooth in the left valve, and the anterior tooth in the 
right; the teeth are sometimes grooved internally, and the 
anterior tooth in ono valve is broad and bifid; and in some 
instances the teeth are obtuse and short; two muscular im¬ 
pressions in each valve, that on the posterior side somewhat 
oblong, and the anterior one sub-orbicular ; pallial impression 
with a large sinus; ligament external, but, in some species, 
nearly concealed by the prominent anterior margin of the 
valves near the beaks. 
1. Petricola inflata. —The Inflated Pctricola, pi. XC. 
figs. 1, 2, 3. 
Sub-triangular, gibbose, and somewhat cordifonn ; beaks 
produced and approximate, anteriorly short, rounded below ; 
posterior side with the hinge-line angular, and obliquely trun¬ 
cated at the terminations; surface smooth, with an obscure 
ridge on the posterior side from the beaks to the margin, and 
with remote shallow lines of growth. 
Found in the Lias, while cutting for Kirby Tunnel beyond 
Coventry. 
2. Petricola l.evis. —The Smooth Petricola, pi. XC.f. 6*, 7. 
Obovate, sub-compressed; beaks rather produced and ap¬ 
proximate ; anterior side rounded and shortest; posteriorly 
lengthened, and a little narrowed; surface smooth, with re¬ 
mote, irregular linos of growth. 
In the Lias, at Barrow. 
3. Petricola laminosa. —The Laminated Petricola, pi. 
XC. figs. 4, 5. 
P. laminosa. Sowerby, VI. p. 142, pi. 573. 
Ovate, gibbose, anterior side shortest and rounded ; poste¬ 
rior side somewhat acuminate ; beaks obtuse and approxi¬ 
mate ; one broad cleft tooth in the left valve, and two small 
ones in the other; surface with erect, laminated, concentric, 
narrow ribs. 
Fig. 5 is probably a distinct species. 
In the Rod Crag, Sutton, and the Coral Crag, Ramshot. 
4. Petricola canaliculata. —The Canaled Petricola. 
P. canaliculata. Sowerby, Geo. Tr. 2d Ser. IV. p. 16, f. 11. 
Orbicular, very convex; beaks nearly central, and approxi¬ 
mate ; surface with numerous longitudinal furrows, which are 
nearly covered over ; internal edge granulated. 
In the Greensand, Blackdown. 
5. Petricola nuciformis. —The Nut-shaped Petricola. 
P. nuciformis. Sowerby, Geo. Tr. 2d Ser. IV. p. 341, pi. 
16, fig. 10. 
Sub-orbicular, very convex ; beaks nearly central, and 
quite approximate ; surface longitudinally striated ; the inter¬ 
nal edge serrated. 
The Greensand, Blackdown. 
Genus XLVIL—SPHENIA.— Turton. 
Shell transverse, inequivalve, inequilateral; general form 
