Nucula. 
CONCHIFERA. 
185 
duced; compressed, and somewhat pointed ; with the surface 
smooth. 
The London Clay, Ilighgate and Sheppey. 
7. Nucula undulata. —The Waved Nucula, pi. LXX\ I. 
figs. G, 7. 
N. undulata. Sowerby, VI. p. 104, pi. 554, fig. 3. 
Globular, its width a little more than its length, and some¬ 
what oblique; posterior side produced, narrowed, and acute ; 
surface concentrically waved. 
The Gault, Folkstone. 
8 . Nucula amygdaloides. —The Almond-shaped Nucula, 
pi. LXXVI. figs. 35, 3G. 
iV. amygdaloides. 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. LXX^ L 
fig. 50. 
N. laevigata . Sowerby, II. p. 207, pi. 192, 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 similis. —The Similar Nucula, pi. I XXVI. 
figs. 28, 19, and 48. 
iV. similis. 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 crcnulated. 
The London Clay, Barton and Ilighgate. 
11 . Nucula trigona. — The Triangular Nucula, pi. 
LXXVI. fig. 43. 
N. trigona. Sowerby, II. p. 208, pi. 192, fig. 5. 
Triangular, compressed ; sides nearly equal; lunette con¬ 
cave ; surface smooth; hinge-pit short; edge crcnulated. 
The London Clay, Barton, Hampshire. 
12 . Nucula pectinata. — The Toothed Nucula, pi. 
LXXVI fig. 54. 
N. pectinata. Sowerby, II. p. 209, pi. 192, figs. G, 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 stria?. 
The Gault, Folkstone and Cambridgeshire ; and the Green¬ 
sand, Blackdown and Lyme Regis. 
13. Nucula 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, gibbosc ; 
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 ; hinge-pit 
minute. 
The London Clay, Barton and Ilighgate. 
14. Nucula palmjea. —The Palm Nucula, pi. LXXVI. 
fig. 39. 
N. palmcea. Sowerby, V. p. 117, pi. 475, fig. 1. 
Transversely elongated, nearly cylindrical, with the ends 
rounded and equal; very gibbose; beaks nearly central ; sur¬ 
face smooth and shining, with irregular lines of growth. 
The Carboniferous Limestone, Derbyshire. 
15. Nucula variabjlis.—T he Variable Nucula, pi- 
LXXVI. figs. 1, 2. 
N. variabilis. 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, Ancliff and Cloughton, and the Inferior 
Oolite, Blue-Wick. 
10. Nucula impressa. —The Impressed Nucula, pi. 
LXXVI. figs. 15, 1G. 
N. impressa. Sowerby, V. p. 1 18, pi. 475, fig. 3. 
Transversely ovate, compressed; sides unequal, the beaks 
situated nearest the posterior extremity ; margin regularly 
curved, except at the lunette; lunette deeply impressed, convex, 
and elongated ; surface smooth ; edges destitute of crenulations. 
The Lower Greensand, Parham and Pnlborough. 
17. Nucula antiquata.—T he Antiquated Nucula, pi 
LXXVI. figs. 3, 4. 
N. antiqudh: 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 crcnulated. 
The Lower Greensand, Pnlborough and Blackdown. 
18. Nucula ovum. —The Egg-shaped Nucula, pi. LXXVI. 
fig. 37. 
N. ovum. Sowerby, V. p. 118, pi. 47G, fig. 1. Phillips, 
Geo. York, 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. 47G, fig. 2. 
Transversely elongated, its width upwards 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 the anterior ex¬ 
tremity ; surfaco with fine concontfic ridges. 
The Lias, Northamptonshire, and Magilligan, Ireland. 
20. Nucula lacryma. —The Tear Nucula, pi. LXXVI. 
fig. 23, 24. 
N. lacryma. Sowerby, V. p. 119, pi. 47G, 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. —The Mucronated Nucula, pi. 
LXXVI. figs. 18, 19. 
N. mucronata. Sowerby, V. p. 120, pi. 476, fig. 4. 
2 s 
