Nucula. 
MOLLUSCA. ARCADiE. 
403 
8. N. ovata . — Transversely ovate, rather depressed, obscurely striated 
transversely ; lunette slightly impressed, cordate, elongated ; margin entire.” 
— Mant. Suss. 94. t. xix. f. 26, 27- — In Blm Chalk Marl. 
9. N. variabilis — Transversely oval elongated, sometimes oblique, rather 
depressed, sm.ooth ; beaks near one end.Sower. Min. Conch, t. cccclxxv. 
£ 2. — In Oolite. 
10. N. lachryma. — Ovate, gibbose, smooth ; anterior side produced, point- 
ed, convex above ; posterior side rounded — Sower. Min. Conch, t. cccclxxvi. 
£ 3. — In Oolite. 
11. N. mucronata — Subrhomboidal, rounded, convex, concentrically sulca- 
ted, anteriorly mucronated. — Sower. Min. Conch, t. cccclxxvi. f. 4 — In Oolite. 
12. N. angulata. — Rhomboidal, concentrically striated ; most convex near 
the beaks ; front rounded — Sower. Min. Conch, t. cccclxxvi. f. 5 — In Green 
Sand. 
13. N. impressa . — Transversely oval, depressed, smooth ; beaks near one 
extremity ; lunette deeply sunk, convex, elongated ; edges entire — Sower. 
Min. Conch, t. cccclxxv. £ 3 . — Green Sand. 
14. N. antiquata. — Triangular, rounded, gibbose, antiquated, longitudinal- 
ly striated ; lunette heart-shaped, sunk ; margin toothed. — Sower. Min. 
Conch. 1. cccclxxv. f. 4 . — Green Sand. 
15. N. ovum — Transversely obovate, ventricose, smooth, anteriorly point- 
ed. — Sower. Min. Conch, t. cccclxxvi. £ 1. — Lias. 
16. N. ventricosa . — Concentrically sulcated; anterior side rounded; poste- 
rior much produced, attenuated ; upon the posterior slope is a broad concave 
area, bounded by two ridges that run from the beak to the extremity ; sulci 
fine. — Sower. Min. Conch, t. cccclxxvi. f. 2. — In Oolite Northamptonshire, 
17 . N. deltoidea. — Triangular, inflated ; posterior side obliquely truncated, 
flat, pointed ; anterior side short, rounded.—jS'Mc^n Min. Conch, t. dIiv. f. 1. 
—Upper Marine Foi'mation, Isle of Wight. 
18. N. inflata — ^Nearly globular, smooth ; the posterior side produced, 
compressed,' pointed.— -(S'ower. Min. Conch, t. dIv. £ 1 . — London Clay. 
19. N. undxdata. — Globular, concentrically undulated ; posterior side pro- 
duced, contracted, pointed — Sower. Min. Conch, t. dHv. £ 3 . — Chalk Marl. 
20. N. amygdaloides — Transversely elliptical, elongated and sulcated, com- 
pressed ; sides equal. — Sower. Min. Conch, t. dHv. f. 4 , — London Clay. 
21. palmcB — Transversely elongated, very convex, shining; extremi- 
ties rounded, equal ; beaks nearly canixdX.— Sower. Min. Conch, t. cccclxxv. 
£ 1 . — Carboniferous Limestone. 
22. N. attenuata — Transversely elongated, ventricose ; one end short 
rounded ; the other produced, with a broad concave area, elevated in the 
middle along the joint ; the whole covered with regular fine concentric ribs, 
or strife. Like the last in form. — Multarticulate Cockle, Cre, Ruth 310, 
t. XV. f. 5. — In slate-clay of the Independent Coal Fo^'mation. 
23. N. Transversely ovate, ventricose, beaks incurved near one 
end, the other slightly produced and obtuse ; obsoletely furrowed concentri- 
cally, with irregular distant grooves — Multarticulate Cockle, Ure^ Ruth. 
310, t. XV. f. 6.—In Slate-clay of the Independent Coal Formation. 
C C S 
