'ECTEN. 



COXCHIFERA. 



■157 



51. Pecten Ottonis. — The Ottonian Pecten, pi. LXI.** 

 fig. C. 



P. Ottonis. Portlock, Geo. Report, p. 436, pi. 3G, fig. 10. 



Sub-orbicular ; a little convex, oblifjuo ; surface with numer- 

 ous longitudinal, sharp, radiating ribs, decussated by fine con- 

 contric striie ; ears uucMjual ; hiugc-line a little triangular; 

 margin cronatcd. 



The Carboniferous Limestone, Fermanagh, Ireland. 



52. Pectex semicostatus. — The Semi-ribbed Pecten, 

 pi. LXI." fig. i. 



P. scmlc'jstatHs. Portland, Geo. Report, p. 436, pi. 36, 

 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. 6, 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. 

 IJ?;Y. fig. 14. 



P. sub/cvdx. Phillips, Geo. York, I. pi. 14, fig. 5. 



Shell convex, nearly orbicular ; ears unequal, blunt ; sur- 

 face with about nineteen rounded, smooth, longitudinal ribs ; 

 margins crenulated. 



The Lias, Bilsdale, Yorkshire. 



56. Pecten dischepans. — The Discrepant Pecten, pi. 

 LXY. fig. 17. 



P. Jiirosiis. (A large 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-imbricateil 

 riba ; margins scolloped. 



In the Kelloways Rock, Scarborough and Hackncss. 



57. Pecten Vai.oniensis. — The Valonian Pecten, pi. 

 LXI.** fig. 12. 



P. Faloniensis. Portlock, Geo. Report, p. 126, 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 striie; surface with numerous rounded, longitudinal 

 irregular ribs, an<l sharj) towards the edge ; part of the pos- 

 terior and anterior margin is finely striated obliquely over 

 the ribs with obsolete linos of jrrowth. 



The Oolite, Aghanloo, Ireland. 



58. Pecten virgiulifebis. — The Whitish Pecten, pi. 

 LXV. fig. 18. 



P. virffuiliferus. Phillips, Geo. York, I. p. 11, fig. 20. 



Oblong, rather flat ; cars uneqiial ; surface with numerous 

 longitudinal, divergent stria^, which are covered with short 

 slightly imbricated scales. 



The Inferior Oolite and Blue Wick, Yorkshire. 



59. Pecten si.mi-lex. — The Simple Pecten, pi. LXV. figs. 

 26, 27. 



P. simplex. Phillips, Geo. York, II. p. 212, pi. 6, fig. 27. 



Oblong-ovate, oblique ; lower valve tumid, with strong, 

 radiating, arched ribs ; uj)per 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. calms. Goldfuss, p. 74, pi. 99, fig. 1. 



Orbicularly ovate, equilateral ; convexo-plano, pellucid, 

 shining, with nearly obsolete radiating stria) ; ears obtusely 

 angular, the anterior the largest. 



The Oolite, Ballentoy, Ireland. 



61. Pecten gentilis. — The Kindred Pecten, pi, LXI.** 

 fig. 2. 



P. gentilis. J. C. Sowerby, Geo. Tr. V. 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, Coalbrook Dale. 



62. Pecten scalaris. — The Ladder Pecten, pi. LXI.** 

 fig. 3. 



P. scalaris. J. C. Sowerby, Geo. Trans. 2d Ser. V. pi. 

 39, fig. 20. 

 The Coal Measures, Coalbrook Dale. 



63. Pecten tkansversus. — The Transverse Pecten, pi. 

 LXI.** fig. 13. 



P. transversus. Sower. Geo. Tr. 2d Ser. V. pi. 53, fig. 3. 

 Phillips. 



Transversely obovato, very slightly convex ; ears large, and 

 nearly equal ; surface with numerous longitudinal ribs, set in 

 threes, and crossed by numerous regular lines of growth. 



64. Pecten nexilis. — The Wreathed Pecten, pi. LXI.** 

 fig. 10. 



P. nexilis. J. C. Sowerby, Geo. Trans. 2d Ser. V. 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. 



65. Pecten compositus. — The- Composite Pecten, pi. 

 LXIV. figs. 12, 13, 14. 



P. compositus. Sowerby, Geo. Trans. 2d Ser. IV. p. 342, 

 pi. 17, fig. 20. 



Oblong, with about twenty sharp, radiating ribs ; and two 

 rows of scales in each of the intervening furrows. 



The Greeusand, Blackdown. 



66. Pecten Millerii. — Miller's Pecten, pi. LXIV. figs- 

 9, 10. 



P. Milerii. Sowerby, Geo. Trans. 2d Ser. IV. p. 342, 

 fisr. 19. 



