206 



CONCH IFERA. 



Cyt 



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 JIus. 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 ovately rounded ; tumid, smooth, and shining ; exter- 

 nal surface provided with nearly obsolete transverse striiB ; 

 striae very slight ; lunulo cordiform ; hinge with three teeth ; 

 lateral teeth large, conical. 



Found in the London Clay at Bracklesham Bay. 



6. Cytherea obliciua. — The Oblique Cytherea, pi. 

 LXXXVI. fig. 24. 



C. ohlhpui. Deshayes, Coq. Foss. pi. 21, figs. 7, 8. 



Shell ovate, oblique, tumid, sub-quadrate, and inequilateral ; 

 umbones obliquely recurved ; lunule large and heart-shaped ; 

 with numerous thin, somewhat irregular, transverse striae ; 

 hinge 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. siih-ejycinoidc's. Deshayes, Coq. Foss. I. p. 129, pi. 22, 

 figs. S, 9. 



Shell transversely ovate, sub-depressed, and provided with 

 numerous rounded, regular, transverse furrows ; lunule small 

 and smooth ; hinge with three divergent teeth ; the posterior 

 one cleft ; the lateral one very small. 



Found in the London Clay at Bracklesham. 



8. Cytherea pusilla. — The Slender Cytherea, pi. 

 LXXXVI. fig. 1 9. 



a pusilla. Deshayes, Coq. Foss. I. p. 137, pi. 22, fig. 

 14. 



Shell small, orbicular, oblique, sub-transverse ; with thin, 

 numerous, transverse striaj ; umbones very small, oblique, and 

 recurved ; destitute of a lunule ; hinge with two teeth in one 

 valve and three in the other ; lateral teeth small. 



Found in the London Clay at Barton. 



9. Cytherea tellinaria. — The 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. LXXXVI. 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 ; lunule large, 

 ovate ; hinge with three teeth ; left valve with the posterior 

 one bifid ; that of the right valve lamellose. 



Found in the London Clay at Bracklesham Bay. 



11. Cytherea trigonula. — The Trigonal Cytherea, pi. 

 LXXXVI. fig. 23. 



C. trigonula. Deshayes, Coq. Foss. I. p. 130, pi. 21, figs. 

 12, 13. 



Shell trigonal, sub-equilateral, smooth, and transversely 

 sub-striated ; umbones small, acuminated, and oblique ; lunule 

 heart-shaped and deep ; hinge with three teeth ; the lateral 

 ones large and elongated. 



In the London Clay at Bracklesham Bay. 



12. Cytherea rugosa. — The Rough Cytherea, pi. 

 LXXXIV. fig. 11. 



C. rurjosa. Sowerby, Geo. Tr. 2d Ser. IV. p. 346, pi. 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 

 are more numerous on the anterior side. 



The Portland Stone, Chlcksgrove and Swindon. 



13. Cytherea dolobra. — The Axe-shaped Cytherea, pi. 

 LXXXIV. fig. 13. 



C. dolohra. 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. 



1 4. Cytherea elegans. — The Elegant Cytherea, pi. 

 LXXXIV. fig. 21. 



C. elegans. Deshayes, Fos. 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-striatedCytherea, 

 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 striae. 



The London Clay, Hampstead, Highgate, and Shoppy. 



16. Cytherea Chione. — Chione's Cytherea, pi. LXXXIV. 

 fig. 18. 



C. Chione. Brown, Illust. Rec. Conch. Brit. p. 91, pi. 37, 

 fig. 2. _ 



Obliquely ovate, moderately convex ; beaks small, a little 

 incurved ; lunette 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. 



The Coral Crag, Ramshot. 



17. Cytherea truncata. — The Truncated Cytherea, pi. 

 LXXXIV. fig. 26. 



Venus (?) truncata. Sowerby, Geo. Tr. 2il Ser. IV. 

 p. 341, pi. 17, fig. 3. 



Sub-quadrate ; beaks placed near the anterior extremity, 

 which is exceedingly short ; posterior side large, and obliquely 



