PLATE LXXXT. 
I, 2. Cypricardia Cymbaeformis. ( Boat-formed Cypricardia .) Transversely oblong; beaks small, incurved ; 
anterior side cordiform ; posterior side, contracted to a point ; valves deep, carinated; beaks short, incurved. 
3. C. Rhombea. (Ehomboidal Cypricardia.) Rhomboidal ; anterior side short, rounded; posterior side large, trun¬ 
cated, with keel from beak to extreme angle of base ; back convex; beaks obtuse. 
4. C. Undata. ( Waved Cypricardia.) Transversely elongated, convex ; surface, with deep, wide undulations; beaks 
short; lunette cordiform; front concave. Length, § in.; breadth, 1 in. 
5. 6 . C. Amygdalina. (Almond-shaped Cypricardia.) Transversely oblong-ovate, smooth ; valves deep, obtusely 
carinated ; anterior side short, cordiform, obtuse; posterior side acute; beaks short, obtuse. Length, 1 in. ; breadth, I 4 in. 
7. C. Deltoidea. (Deltoidal Cypricardia.) Ovate, rhomboidal, compressed; anterior side rounded; posterior side 
truncated, with ridge from beaks to base; beaks obtuse; base rounded ; surface smooth. 
8 . Cardiomorpha Oblonga. (Oblong Cardiomorpha.) Oblong, sub-compressed, very short; beaks incurved; posterior 
side large; hinge-line straight; surface smooth. 
9. C. Solenoides. (Solen-formed Cypricardia.) Transversely elongated, compressed; beaks obtuse; anterior side 
short, rounded ; posterior side sub-truncated, with produced point; lunette large, deep. Length, § m.; breadth, 1-J-in. 
10. C. Glabrata. (Very Smooth Cypricardia.) Transversely rhomboidal; anterior side short, straight; posterior side, 
with oblique keel from beak to margin ; surface glossy, with transverse sulci; basal lino straight. 
II. C. Pectenifera. (Pectinated Cypricardia.) Transversely sub-quadrangular, with keel from beak to base ; surface, 
with longitudinal sulci and three or four, erect lamellae, pectinated upon lower sides ; anterior side smooth, truncated. 
12. C. Retusa. (Blunted Cypricardia.) Cordiform, smooth, sub-depressed; beaks long, large, sub-acute; anterior 
side pointed ; posterior side long. Length, £ in.; breadth, 1 in. 
13. C. Tricostata. (Three-ribbed Cypricardia.) Transversely elongated, inflated; hinge-line lengthened, straight; 
anterior side short, rounded; posterior side, with strong, diagonal ridge from beak to margin; above this two other ridges, 
one parallel, close to hinge-line ; surface, with concentric strite. 
14. C. Impressa. (Impressed Cypricardia.) Transversely oblong-ovate, inflated, smooth; liinge-line long, straight ; 
anterior sido truncated; posterior side obtusely pointed; base concave; beaks blunted; with slight flexure towards base. 
Length, in. ; breadth, If in. 
15. Edmondia Unioniformis. (TJnio-formed Jfidmondia.) Transverse, ovate, gibbose ; anterior side short, rounded; 
beaks obtuse, incurved, approximate ; base arcuated ; surface of posterior side, with transverse wrinkles. 
16. Cardium Porulosum. (Porous Cardium.) Orbicular ; right side slightly truncated; surface, with many, longi¬ 
tudinal sulci; with a series of erect, sub-acute, approximating spines on intervening spaces ; margin denticulated ; hinge- 
line straight. 
17. C. Aculeatum. (Prickly Cardium.) Elongated, obliquo; anteriorly short; surface, with many, longitudinal, 
triangular ribs, with a series of sharp, curved spines; sulci, with transverse strife. 
18. C. Globosum. (Globular Cardium.) Orbicular, inflated; surface smooth, with many, fine, concentric stria); 
posterior side flattened below beaks. 
19. C. Proboscideum. (Produced Cardium.) Gibbose, sub-orbicular; anterior side parallel; surface, with about 
twenty, longitudinal ribs, each with many, channelled, conical spines, with two series of smaller ones between each. 
20. C. Parkinsoni. (Parkinsons Cardium.) Gibbose, oblique ; posterior sido somewhat parallel; with thirty-eight to 
forty, longitudinal ribs, with transverse elevations on each. 
21. C. Striatum. (Striated Cardium.) Sub-orbicular, convex; beaks prominent; surface, with many, longitudinal, 
divergent strife. Length, If in. ; breadth, If in. . 
22. c. Plumstediense. (Plumsted Cardium.) Sub-cordate, smooth; anterior side, with longitudinal sulci; serrations 
on edge of shell acute, with transverse, irregular lines of growth. 
23. C. Echinatum. (Spined Cardium.) Convex, orbicular ; with about eighteen, irregular ribs, with a row of many, 
inflected spines; intervening sulci, with transverse strife. 
24. C. Acutangulum. (Acute-angled Cardium.) Sub-triangular; anterior side rounded; posterior side flattened; 
oblique truncated, with ridge from beak, ending in an acute angle on margin; surface smooth. 
25. 26. c. Truneatum. (Truncated Cardium.) Gibbose, transversely ovate, smooth; posterior side obliquely trun- 
cated, with longitudinal strife; beaks small. . ...... 
27. c. Striatulum. (Small-striated Cardiitm.) Convex, orbicular; posterior side, with longitudinal strife, ending in 
dentated margin ; surface concentrically striated. 
b ( 100 ) 
