*206 
CONCH IFERA. 
Cytherea. 
Sub-triangular; beaks nearly central ; sides abruptly slop¬ 
ing from the beaks; base rather straight; surface with shal¬ 
low, concentric furrows. 
The Plastic Clay, CastleHill, Newhaven. 
5. Cytherea nitidula. —The Shining Cytherea, pi. 
LXXXVI. fig. 4. 
C. nitidula. Lamarck, Ann. du Mus. VII. p. 133, No. 3 
et 12, pi. 40, f. 1, 2. Defrance, Diet, des Sc. Nat. XII. p. 421. 
Deshayes, Coq. Foss. I. p. 134, pi. 21, figs. 314, 315, 316. 
Shell ovatoly rounded; tumid, smooth, and shining; exter¬ 
nal surfaco provided with nearly obsolete transverse strife; 
striae very slight; 1 unulo cordiforin ; hinge with three teeth ; 
lateral teeth large, conical. 
Found in the London Clay at Bracklesham Bay. 
6. Cytherea obliq.ua, — The Oblique Cytherea, pi. 
LXXXVL fig. 24. 
C. obliqua. Deshayes, Coq. Foss. pi. 21, figs. 7, 8. 
Shell ovate, oblique, tumid, sub-quadrate, and inequilateral; 
umbones obliquely recurved; lunule largo and heart-shaped; 
with numerous thin, somewhat irregular, transverse striae ; 
Lingo with three teeth, the posterior one bifid. 
Found in the Plastic Clay at Stratford. 
7. Cytherea sub-erycinoides. —The Erycina-like Cy¬ 
therea, pi. LXXXVI. fig. 25. 
C. suberycinoidcs. Deshayes, Coq. Foss. I. p. 129, pi. 22, 
figs. 8, 9. 
Shell transversely ovate, sub-depressed, and provided with 
numerous rounded, regular, transverse furrows; lunule small 
and smooth ; hinge with threo divergent teeth ; the posterior 
one cleft; the lateral one very small. 
Found in the London Clay at Bracklesham. 
8. Cytherea pusilla.—T he Slender Cytherea, pi. 
LXXXVI. fig. 19. 
C. pusilla. Deshayes, Coq. Foss. I. p. 137, pi. 22, fig. 
14. 
Shell small, orbicular, oblique, sub-transverse; with thin, 
numerous, transverse stria?; umbones very small, oblique, and 
recurved ; destitute of a lunule; hinge with two tcoth in one 
valve and three in the other; lateral teeth small. 
Found in the London Clay at Barton. 
9. Cytherea tellinaria.—T he Tellina-like Cytherea, pi. 
LXXXVI. fig. 15. 
C . tellinaria . Lamarck, Ann. du Mus. VII. p. 135, No. 6 
et XII. pi. 40, fig. 4, lb. Ann. Sans. Part V. p. 582, No. 9. 
Deshayes, Coq. Foss. I. p. 130, pi. 22, figs. 4, 5. 
Shell transversely-ovate, trigonal, smooth, sub-striated, 
transversely and posteriorly sinuated; lunule large, and 
ovately oblong ; hinge with three cardinal teeth ; the two an¬ 
terior ones approximate. 
In the London Clay at Barton. 
10. Cytherea sulcataria. —The Furrowed Cytherea, 
pi. LXXXVL fig. 21. 
C. sulcataria. Deshayes, Coq. Foss. I. p. 133, pi. 20, 
figs. 14, 15. 
Shell ovate, tumid, sub-transverse, inequilateral; trans¬ 
versely furrowed; umbones small and oblique; lunulo large, 
ovate; hinge with three teeth ; left valve with the posterior 
one bifid ; that of the right valve lamellose. 
Found iu the London Clay at Bracklesham Bay. 
11. Cytherea trigonula. —The Trigonal Cytherea, pi. 
LXXXVL fig. 23. 
C. trigonula. Deshayes, Coq. Foss. I. p. 139, pi. 21, figs. 
12,13. ' r* ' ' 
Shell trigonal, sub-equilateral, smooth, and transversely 
sub-striated ; umbone^mall, acuminated, and oblique ; lunule 
heart-shaped and deep ; binge with three teeth ; tho lateral 
ones large and elongated. 
In the London Clay at Bracklesham Bay. 
12. Cytherea rugosa. — The Rough Cytherea, pi. 
LXXXIV. fig. 11. 
C. rugosa. Sowcrby, Geo. Tr. 2d Ser. IV. p. 346, pl.^22, 
fig. 13. 
Sub-triangular, acuminated towards the beaks, which are 
produced; posterior extremity pointed ; valves very convex 
near the beaks; surface with many concentric furrows, which 
arc more numerous on tho anterior side. 
The Portland Stone, Chicksgrove and Swindon. 
13. Cytherea dolobra. —Tho Axe-shaped Cytherea, pi. 
LXXXIV. fig. 13. 
C. dolobra. Phillips, Geo. York, pi. 9, fig. 12. 
Sub-triangular; moderately convex ; beaks produced; lunette 
very narrow ; posterior side a little concave under the beaks ; 
posterior side rather straight; surface smooth, with a few 
remote lines of growth. 
The Cave Oolite, Cloughton Wyke, Yorkshire. 
14. Cytherea elegans.— The Elegant Cytherea, pi. 
LXXXIV. fig. 21. 
C. elegans. Deshayes, Eos. Coq. pi. 20, fig. 89. Venus. 
Sowerby, V. p. 26, pi. 422, fig. 3. 
Obovate, moderately convex; beaks obtuse, lunette oval; 
surface glossy, and concentrically furrowed, the intervening 
spaces a little rounded. 
The London Clay, Barton and Bracklesham Bay. 
15. Cytherea tenui-striata.— The Thin-striatedCythcrea, 
pi. LXXXIV. figs. 22, 23. 
Venus tenui-striata. Sowerby, Geo. Trans. 2d Ser. V. 
p. 136, pi. 8, fig. 8. 
Sub-triangular, gibbose; nearly smooth; anterior side a 
little concave; beaks prominent; lunette rather broad, and 
pointed at both extremities ; surface with numerous very close 
concentric stria?. 
The London Clay, Hampstead, Higbgate, and Sheppy. 
16. Cytherea Ciiione.— Chione'sCytherea, pi. LXXXIV. 
fig. 18. 
C. Chione. Brown, Illusfc. Rec. Couch. Brit. p. 91, pi. 37, 
fig. 2. 
Obliquely ovate, moderately convex; beaks small, a little 
incurved ; lunetto cordiform ; surface smooth and shining, with 
a few concentric shallow lines of growth ; margins thick and 
rounded; pallial impression with a broad transverse sinus, 
acuminated at the point. 
Tho Coral Crag, Ramshot. 
17. Cytherea truncata.— The Truncated Cytherea, pL 
LXXXIV. fig. 26. 
Venus (?) truncata . Sowerby, Geo. Tr. 2d Ser. IV. 
p. 341, pi. 17, fig. 3. 
Sub-quadrate; beaks placed near tho anterior extremity, 
which is exceedingly short; posterior side large, and obliquely 
