N 



I'Cl'LA. 



CONCHIFERA. 



185 



iliicod ; compressed, and somewhat pointed ; with tlio surface 

 siuootb. 

 The London Clay, Ilighgate and Sheppey. 



7. NucuLA UNDULATA. — The Waved Nucula, pi. LXXVI. 

 figs. 6, 7. 



N. undulata. Sowerby, VI. p. 10 1, j)!. 5.54, fig. 3. 



Globular, its width a little more than its length, and some- 

 what oblinuo ; posterior side produced, narrowed, and acute ; 

 surface concentrically waved. 



The Gault, Folkstono. 



8. XicuLA AMYGDAl.oiDEs. — Tho Aliiumd-shaped Nucula, 

 pi. LXXVI. figs. 3j, 36. 



N. amygdalo'ules. Sowerby, VI. p. 104, pi. 554, fig. 4. 



Transversely elliptical, elongated, compressed, its width be- 

 ing nearly double its length ; sides equal, surface with numer- 

 ous small, regular, transverse furrows. 



The London Clay, Sheppey and Hampstead. 



9. Nucula laevigata. — The Smooth Nucula, pi. LXXVI. 

 fig. 50. 



X. Iwvigata. Sowerby, II. p. 207, pi. UI2, figs. 1, 2. 



Transversely elliptical, convex ; posterior side truncated ; 

 lunette impressed, convex and oblong, with surface smooth ; 

 edge entire ; a pit or compressed tooth in the hinge. 



The Red Crag, Walton, Naze, and the Coralline Crag, 

 Sutton. 



10. Nucula .sijiilts. — The Similar Nucula, pi. I XXVI- 

 figs. 28, 19, and 48. 



iV. shnilis. Sowerby, II. p. 207, pi. 192, f. 3, 4, and 10. 



Transversely obovate, compressed ; posterior side straight ; 

 lunette oblong, sunk, concave in the middle ; surface longitu- 

 dinally striated ; edge crenulated. 



The London Clay, Barton and Highgate. 



11. Nucula trigona. — The Triangular Nucula, pi. 

 LXXVI. fig. 43. 



N. triyona. Sowerby, II. p. 208, pi. 192, fig. 5. 

 Triangular, compressed ; sides nearly equal ; lunette con- 

 cave ; surface smooth ; hinge-pit short ; edge crenulated. 

 The London Clay, Barton, Hampshire. 



12. Nucula pectinata. — The Toothed Nucula, pi. 

 LXXVL fig. 54. 



N. pectinata. Sowerby, II. p. 209, pi. 192, figs. (!, 7. 



Transversely elliptical, elongated, convex ; posterior side 

 truncated ; lunette sunk, flat, and heart-shaped ; surface with 

 numerous small divergent furrows, which are intersected by 

 very fine transverse striae. 



The Gault, Folkstone and Cambridgeshire ; and the Green- 

 sand. Blackdown and Lyme Regis. 



13. NccuLA MINIMA. — ^The Small Nucula, pi. LXXVI. 

 fig. 53. 



N. minima. Sowerby, II. p. 209, pi. 192, figs. 8, 9. 



Transversely ovate, nearly twice as wide as long, gibbose ; 

 posterior side pointed ; lunette straight and elongated, reach- 

 ing from the beak to the angle of the posterior side ; surface 

 transversely striated ; edge without crenulations ; binge-pit 

 minute. 



Tho London Clay, Barton and Highgate. 



14. NncuLA pal.m^a. — The Palm Nucula, pi. LXXVI. 

 fig. 39. 



iV. palmaa. Sowerby, V. p. 117, pi. 475, fig. 1. 



Transversely elongated, nearly cylindrical, with the ends 

 rounded and equal ; very gibl)0se ; beaks nearly central ; sur- 

 face smooth and shining, with irregular lines of growth. 



The Carboniferous Limestone, Derbyshire. 



15. Nucula variabilis. — The Variable Nucula, pi- 

 LXXVI. figs. 1, 2. 



-V. variabUis. Sowerby, V. p. 117, pi. 475, fig. 2. 



Transversely ovate, elongated ; sometimes oblique ; rather 

 compressed ; sides unequal ; beaks placed near to the posterior 

 side, which is usually less rounded than the other ; valves 

 deepest towards the beaks ; surface smooth ; lunette inconspi- 

 cuous. 



The Great Oolite, Anclift" and Cloughton, and the Inferior 

 Oolite, Blue-Wick. 



16. Nucula impressa. — Tho Impressed Nucula, pi. 

 LXXVI. figs. 15, 16. 



N. impressa. Sowerby, V. p. 118, pi. 475, fig. 3. 



Transversely ovate, compressed; sides unequal, the beaks 

 situated nearest the posterior extremity ; margin regularlv 

 curved, except at the lunette; lunette deeply impressed, convex, 

 and elongated ; surface smooth ; edges destitute of crenulations. 



The Lower Greensand, Parham and Pulborough. 



17. Nucula antiquata. — The Antiquated Nucula, pi 

 LXXVI. figs. 3, 4. 



N. antiquiita. Sowerby, V. p. 118, pi. 475, fig. 4. 



Triangular, rounded, inflated, and antiquated ; beaks in- 

 curved, and nearly touching ; lunette cordiform and sunk ; 

 surface longitudinally striated ; margin crenulated. 



The Lower Greensand, Pulborough and Blackdown. 



18. Nucula ovum. — The Egg-shaped Nucula, pi. LXXVI. 

 fig. 37. 



N. ovum. Sowerby, V. p. 118, pi. 476, fig. 1. Phillips, 

 Geo. Yorkj I. pi. 12, fig. 4. 



Transversely obovate, inflated and smooth ; pointed a little 

 anteriorly ; posterior side regularly rounded ; almost as deep 

 as long. 



The Lias, Whitby, Yorkshire. 



19. Nucula claviformis. — The Club-shaped Nucula, pi. 

 LXXVI. fig. 38. 



N. claviformis. Sowerby, V. p. 119, pi. 476, fig. 2. 



Transversely elongated, its wiilth ujiwards of twice its 

 length ; ventricose ; anterior side rounded ; much produced 

 and attenuated, and slightly truncated posteriorly, on which 

 side there is a broad concave area, bounded by two ridges, 

 emanating from the beaks, and terminating on tho anterior ex- 

 tremity ; surface with fine concentric ridges. 



The Lias, Northamptonshire, and Magilligan, Ireland. 



20. NucnLA LACRYMA. — The Tear Nucula, pi. LXXVI. 

 fig. 23,. 24. 



N. lacryma. Sowerby, V. p. 119, pi. 476, fig. 3, Phillips, 

 Geo. York, I. pi. 11, fig. 14. 



Ovate, ventricose ; its width twice its length ; anterior side 

 produced, pointed, and convex above ; posterior side rounded : 

 surface smooth. 



The Great Oolite, Ancliff and Cloughton, and the Inferior 

 Oolite, Blue-Wick, Yorkshire. 



21. Nucula mucronata. — Tho Mucronatcd Nucula, pi. 

 LXXVI. figs. 18, 19. 



N. mucronata. Sowerby, V. p. 120, pi. 476, fig. 4. 



2s 



