Pecten. 
COXCHIFERA. 
157 
51. Pecten Ottonis. —The Ottonian Pecten, pi. LXI.** 
fig. 6. 
P. Ottonis. Portlock, Geo. Report, p. 430, pi. 30, fig. 10. 
Sub-orbicular; a little convex, oblique ; surface with numer¬ 
ous longitudinal, sharp, radiating ribs, decussated by fine con¬ 
centric striae; ears unequal; hinge-line a little triangular; 
margin crenated. 
The Carboniferous Limestone, Fermanagh, Ireland. 
52. Pecten semicostatus. —The Semi-ribbed Pecten, 
pi. LXI.** fig. 4. 
P. semicoslat us. Portland, Geo. Report, p. 430, pi. 30, 
fig. 9. 
Nearly orbicular, convex; ears almost equal, the posterior 
one square, the anterior somewhat more pointed ; surface with 
numerous rounded ribs, extending from the base about half¬ 
way to the beak. 
The Carboniferous Limestone, Tyrone. 
53. Pecten sexcostatus. —The Six-Ribbed Pecten, pi. 
LXI.* fig. 7, 8. Woodward, Geo. Nor. pi. 5, fig. 29. 
Triangular, convex, with small, nearly equal ears ; beak of 
the larger valve incurved, and receiving the smaller flat valve, 
both valves with six pretty large, longitudinal, divergent ribs; 
margins deeply crenated. 
The Upper Chalk, Harford Bridge, Norfolkshire. 
54. Pecten stellaris. —The Little Star Pecten, pi. LXV. 
fig. 7. 
P. stellaris. Phillips, Geo. York, II. p. 212, pi. 0, fig. 18. 
Sub-orbicular, with about fifteen strong, smooth, longitudinal, 
divergent ribs. 
The Carboniferous Limestone, Yorkshire. 
55. Pecten subl/EVis. —The Half-smooth Pecten, pi. 
LXY. fig. 14. 
P. Sublmvis. Phillips, Geo. York, I. pi. 14, fig. 5. 
Shell convex, nearly orbicular; cars unequal, blunt; sur¬ 
face with about nineteen rounded, smooth, longitudinal ribs ; 
margins crenulated. 
The Lias, Bilsdale, Yorkshire. 
50. Pecten discrepans. —The Discrepant Pecten, pi. 
LXY. fig. 17. 
P. fibrosus . (A largo variety.) Phillips, Geo. York, I. 
p. 112, pi. G, fig. 3. 
Sub-orbicular; ears nearly equal, with obliquely longitudinal 
ribs, which render the hinge-line uneven ; surface with about 
twelve large, rounded, longitudinal, divergent, sub-imbricated 
ribs; margins scolloped. 
In the Kelloways Rock, Scarborough and Ilackness. 
57. Pecten Valoniensis. —The Valonian Pecten, pi. 
LXI.** fig. 12. 
P. Yaloniensis. Portlock, Geo. Report, p. 120, pi. 25 A, 
figs. 14, 15. 
Sub-orbicular; ears nearly equal and blunt; the larger 
one with radiating, small ribs, crossed by numerous close-set, 
longitudinal striae; surface with numerous rounded, longitudinal 
irregular ribs, and sharp towards the edge ; part of the pos¬ 
terior and anterior margin is finely striated obliquely over 
the ribs with obsolete lines of growth. 
The Oolite, Aghanloo, Ireland. 
58. Pecten virguiliferus. —The Whitish Pecten, pi. 
LXY. fig. 18. 
P. virguiliferus. Phillips, Geo. York, I. p. 11, fig. 20. 
Oblong, rather flat; ears unequal; surface with numerous 
longitudinal, divergent stria*, which are covered with short 
slightly imbricated scales. 
The Inferior Oolite and Blue Wick, Yorkshire. 
59. Pecten simplex. —The Simple Pecten, pi. LXY. figs. 
2G, 27. 
P. simplex. Phillips, Geo. York, II. p. 212, pi. 0, fig. 27. 
Oblong-ovate, oblique ; lower valve tumid, with strong, 
radiating, arched ribs ; upper valve considerably flatter, with 
the furrows corresponding, but flatter ; ears of medium size ; 
hinge-line oblique. 
The Carboniferous Limestone, Bolland. 
GO. Pecten calvas. —The Bald Pecten, pi. LXI.** fig. 
17. P. calvas. Goldfuss, p. 74, pi. 99, fig. 1. 
Orbicularly ovate, equilateral; eonvexo-plano, pellucid, 
shining, with nearly obsolete radiating striae ; ears obtusely 
angular, the anterior the largest. 
The Oolite, Ballentoy, Ireland. 
Gl. Pecten gentilis. —The Kindred Pecten, pi. LXI.** 
fig. 2. 
P. gentilis. J. C. Sowerby, Geo. Tr. Y. 2d Ser. pi. 39, 
fig. 19. 
Ovate, convex, smooth, with fifteen slightly elevated, longi¬ 
tudinal, divergent ribs, which are alternately long and short; 
ears equal and of medium size. 
The Coal Measures, Coal brook Dale. 
62. Pecten sc a laris. —The Ladder Pecten, pi. LXI.** 
fig. 3. 
P. scalar is. J. C. Sowerby, Geo. Trans. 2d Ser. Y. pi. 
39, fig. 20. 
The Coal Measures, Coalbrook Dale. 
G3. Pecten transversus. —The Transverse Pecten, pi. 
LXI."* fig. 13. 
P. transversus. Sower. Geo. Tr. 2d Ser. Y. pi. 53, fig. 3. 
Phillips. 
Transversely obovate, very slightly convex; ears large, and 
nearly equal; surface with numerous longitudinal ribs, set in 
threes, and crossed by numerous regular lines of growth. 
G4. Pecten nexilis. —The Wreathed Pecten, pi. LXI.** 
fig. 10. 
P. nexilis. J. C. Sowerby, Geo. Trans. 2d Ser. Y. pi. 53, 
figs. 1, 2. 
Sub-orbicular, slightly convex, somewhat inequilateral; ears 
large, nearly equal, radiated ; the anterior one less so than the 
other; whole surface with very fine longitudinal divergent 
ribs. 
Devonian Shales, Barnstaple. 
G5. Pecten composites. —The Composite Pecten, pi. 
LXIY. figs. 12, 13, 14. 
P. compositus. Sowerby, Geo. Trans. 2d Ser. 1Y. p. 342, 
pi. 17, fig. 20. 
Oblong, with about twenty sharp, radiating ribs; and two 
rows of scales in each of the intervening furrows. 
o 
The Greensand, Blackdown. 
GO. Pecten Millerii. —Miller's Pecten, pi. LXIY. figs- 
9, 10. 
P. Milerii. Sowerby, Geo. Trans. 2d Ser. IY. p. 342, 
fig. 19. 
