PLATE LXXVI. 
I, 2. Nueula Variabilis. (Variable Nucula.) Transversely ovate, elongated; compressed; sides unequal; surface smooth; lunette small. 
3, 4. N. Antiquata. (Antiquated Nucula.) Triangular, inflated, antiquated; beaks incurved, close ; lunette cordiform ; surface longitudinally 
striated; margin crenulated. J 
5. N. Elongata. (Elongated Nucula.) 
6, 7. N. Undulata. (Waved Nucula.) Globular, oblique ; posterior side produced, narrow, acute; surface concentrically waved. 
8,9,10. N. Lineata. (Lineated Nucula.) Elliptical; beaks central, small ; anterior side rounded; posterior side truncated; surface, with 
transverse strife. 
II, 12. N. Inflata. (Injlated Nucula.) Globular; posterior side small, produced ; compressed, pointed; surface smooth. 
13, 14. N. Apiculata. (Dee-like Nucula.) Sub-orbicular, convex ; anterior side rounded; posterior side concave above; surface smooth. 
15, 16. N. Imppessa. (Impressed Nucula.) Transversely ovate, compressed; sides unequal; margin curved, except at lunette; lunette 
impressed, convex, elongated; surface smooth. 
17. N. Ovata. (O ante Nucula.) Ovate; anterior side short, truncated ; posterior side elongated, rounded ; beaks obtuse ; surface smooth. 
18,19. N. MllCPOnata. (Mucronated Nucula.) Sub-rhomboidal ; ventricose; anteriorly mucronated ; surface, with concentric sulci. 
20. N. Lachrima. (Tear Nucula.) Ovate, ventricose ; anterior side produced, pointed, convex ; posterior side rounded; surface smooth 
(A variety.) 
21. Trigonia Daedalea. (Handsome Trigonia.) Oblong-oval, trigonal ; with tuberculated ridge dividing valves ; with double floxure beneath 
centre of posterior side; beaks small, pointed; anterior side, with many, large tubercles. 
22. N. Lsevis. (Smooth Nucula.) Oval, transversely elongated, smooth, ventricose; beaks large, acute. Length, 3 in.; breadth, 4 in. 
23. 24, 25. N. Lachrima. (Tear Nucula.) V. Fig. 20. 
26. N. Subrecurva. (Sub-recurved Nucula.) Transversely oblong-ovate ; anterior sido acute ; posterior side rounded ; beaks obtuse ; surface 
smooth. 
27. N. Complanata. (Flattened Nucula.) Transversely elongated; anterior side rounded; posterior side concave above, sub-truncated 
below ; surface smooth. 
28. 29, 48. N. Similis. (Similar Nucula.) Transversely obovate, compressed; posterior side straight; lunette oblong, sunk, concave- 
surface, with longitudinal stria) ; edge crenulated. 
30. N. Dubia. (Dubious Nueula.) Transversely oblong-ovate ; extremities pointed ; beaks obtuse, central; base rounded; surface smooth. 
31, 32. N. Angulata. (Angled Nucula .) Ithomboidal ; front rounded ; sides equal, angular; convex near beaks ; surface, with concentric sulci. 
33. N. Ovalis. (Oval Nucula.) Transversely ovate, smooth, convex ; beaks sub-acute. Length, ^ iu.; breadth, £ in. 
34. N. Axiniformis. (Canopy-formed Nucula.) Transversely elongated; anterior side endiug in acute point; dorsal line straight; basal 
line straight; posterior side sub-acute ; beaks obtuse; surface smooth. 
35. 30. N. Amygdaloides. (Almond-shaped Nucula.) Transversely elliptical, compressed; sides equal; surface, with many, transverse sulci. 
37. N. Ovum. (Egg-shaped Nucula) Transversely obovate, inflated, smooth ; anteriorly pointed ; posterior sido rounded. 
38. N. Claviformis. (Club-shaped Nucula .) Transversely elongated ; ventricose; anterior sido rounded; produced, attenuated; with two 
ridges from beaks ; surface, with concentric ridges. 
39. N. Palmse. (Palm Nucula.) Transversely elongated, cylindrical; rounded and equal ends; gibbose, beaks central; surface smooth 
shining, with lines of growth. 
40. N. Elliptica. (Elliptical Nucula.) Elliptical; ends rounded; anterior side short; beaks large ; surface smooth. 
41. T. Affinis. (Allied Trigonia.) Transversely ovate ; anterior sido smooth, with flattened ridges; posterior side produced, sub-truncated 
beakea; basal line straight; beaks obtuse. 
42. T. Incurva. (Incurved Trigonia.) Transversely elliptical ; convex ; posteriorly flattened ; surface tuberculate. 
43. N. TrigOlia. (Triangular Nucula.) Triangular, compressed ; sides equal; lunette concave ; surface smooth ; hinge-pit short; edge 
crenulated. 
44. N. Bivirgata. (Double-Streaked Nucula.) Obliquely sub-triangular, convex ; back curved ; posterior side concave ; base arcuated ; beaks 
obtuse, close ; surface, with two sets of linear sulci; lunette broad ; two transverse bauds near base. 
45. T. Eccentrica. (Eccentric Trigonia.) TrausverBely sub-triangular, convex ; anterior side short; posterior side elongated, truncated • 
beaks obtuse, close ; surface, with transverse, shallow sulci, crossed by shallow ones. 
46. 47. N. Pisum. (Pea Nucula.) Sub-orbicular, convex; beaks obtuse, close; Bides rounded ; surface smooth. 
49. N. Obtusa. (Obtuse Nucula.) Transversely ovate, convex, smooth ; lunette prominent, elongated ; beaks obtuse. 
50. N. Laevigata. (Smooth Nucula.) Transversely elliptical, convex ; posterior side truncated ; lunotte impressed, convex, oblong ; surface 
smooth ; edge entire; pit in hinge. 
51. N. Deltoidea. (Deltoidal Nueula) Triangular, ventricose; anterior side short, rounded; posterior sido truncated, pointed; smooth 
sometimes striated. * 
52. N. Lanceolata. (Lance-shaped Nucula.) Transversely lanceolate, ovate; sides equal; beaks produced; surface smooth; hinge, with 
deltoidal, concave space ; margiu entire ; shell strong. 
53. N. Minima. (Small Nucula) Transversely ovate, gibbose; lunette straight, elongated ; surface transversely striated ; edge entire • 
hinge-jut minute. 
54. N. Pectinata. (Toothed Nucula.) Transversely elliptical, convex; posterior side truncated; lunette flat, cordiform; surface, with 
many, small sulci, crossed by transverse stria?. 
55. N. Cobboldi. (CobbohVs Nucula.) Transversely obovate, convex ; posterior side short, with many, zigzag sulci; margin entire. 
56. 57. N. Accipiens. (Admitted ftucula.) Transversely elongated, oblong-oval, compressed; anterior side rounded ; posterior side truncated • 
beaks central; surface, with fine, concentric strife. * 
58. N. Acuta. (Acute Nucula.) Transversely oblong, convex ; anterior side rounded; posterior side acuminated; beaks acute, sub-central • 
surface, with fine, concentric strife. 
59. N. iEqualis. (Equal Nucula.) Transversely sub-ovate, convex ; anterior side short, rounded; posterior side truncatod; surface, with 
many, concentric ridges. 
60. 61. N. Striata. (Striated Nucula.) Transversely elliptical; anterior side short, pointed; posterior side rounded, acute above ; hinge-line 
straight ; surface, with line, concentric strife. 
62. N. Plicata. (Plicated Nucula.) Obliquely ovate, compressed; beaks prominent; surface smooth, shining, with concentric stria). 
63, 64. N. Compressa. (Compressed Nucula.) Sub-ovate, smooth, compressed; anterior side short, contracted, pointed ; posterior side large 
rounded; base arcuated ; without lunette. 
65. N. Radiata. (Raged Nucula.) Transversely elongated; anterior side rounded; posterior side acute, truncated; flattened space, with 
filiform strife ; beaks well defined. 
66, 67. N. Pygmsea. (Pigmy Nucula.) Sub-triangular; anterior side pointed; posterior side rounded; base arcuated; beaks obtuse* 
surface smooth. * 
68,69. N. Longirostra. (Long-billed Nucula.) Claviform, elongated, convex ; anterior side rounded ; posterior side lengthened, with acute 
ead ; beaks short, incurved. 
70. N. Attenuata. I Attenuated Nucula.) Transversely elongated, arcuated, ventricose; anterior side short, truncated; posterior side 
attenuated ; hinge-area wide, concave ; beaks produced, incurved; surface, with delicate, transverse strife ; base arcuated. 
71. N. Lsevirostra. (Smooth-beaked Nucula.) Oblong-ovate, club-shaped ; anterior side short, rounded ; posterior side lengthened, obtuse • 
beaks obtuse ; surface, with concentric strife. 
72. N. Cuneata. (Wedge-shaped Nucula.) Transversely elongated; cuneiform; beaks obtuse; hinge-line straight; surface, with remote 
ftria) and concentric Hues of growth. 
73. N. LatiSSima. ( Very broad Nucula.) Oblong-ovate; extremities equally rounded, with produced angle above. 
74. N. Brevirostra. (Short-beaked Nucula.) Ovate; anterior side short, attenuated; posterior side large, rounded; beak short; surface 
with concentric strife. 
75. N. Nllda. (Dare Nucula.) Transverselyeiongated; anterior side short; posterior side elongated ; beaks obtuse; surface smooth. 
76. 77. N. Wetherellii. (WetherelVs Nucula.) Orbicular, gibbose, smooth ; beaks small, central; hinge-line triangular ; margin crenulated. 
78, 79. N. Gibbosa. (Tumid Nucula.) Transversely ovate, ventricose; anterior side short; posterior longer, rounded; beaks obtuse, 
incurved; surface, with shallow lines of growth. 
80, 81. N. Luciniformis, (Lucimi-formed Nucula.) Obliquely ovate, inflated, smooth ; anterior side rounded ; posterior side truncated, with 
narrow strife ; base arcuated. 
82, 83. N. Bowerbankii. (Bowerbanlc's Nucula.) Sub-elliptical, convex ; anterior side truncated, with flat lunette ; posterior side rounded; 
surface smooth, striated internally ; edge toothed. 
84, 85. N. Oblongoidea. (Oblong Nucula.) Transversely ovate, lanceolate, inequilateral; anterior side rounded; posterior side acuminated; 
lunule lanceolate ; surface smooth. 
86, 87. N. Semistriata. (Half -striated Nucula.) Transversely ovate, inequilateral; anterior side rounded, smooth; posterior side 
acuminated, with transverse strife ; shell thin. 
88,89. N. Trigonula. (Trigonal Nucula.) Ovate, deltoidal, tumid ; beaks prominent; lunule imbedded ; surface smooth; internal margiu 
crenulated. 
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