922 



CONCHIFERA. 



CoRBULA. 



C. longirostrum. Deshayes, Coq. Foss. p. 52, pi. 7, figs. 20, 

 21. TeUinacuspidata,(?) Olivi, Zoologia Adriatica, p. 101, 

 pi. 4, fig. 3. 



Shell transversely ovate, with thin concentric striae j a long 

 beak in front ; umbones very small. 



Found in the London Clay at Bracklesbam. 



3. CoKBULA STRIATA. — Striated Corbula, pi. XCI. fig. 15. 

 C. striata. Lamarck, Ann. du Mus. VIIL p. 467, No. 3. 



lb. An. San. Ver. V. p. 497, No. 13. 



Shell transversely oval, with a short beak ; surface covered 

 with numerous fine, thin, transverse striae. 



Found in the London Clay at Bracklesbam and Barton. 



4. CoRBFLA DMBONELLA. — The Little Shield Corbula, pi. 

 XCL fig. 89. 



C. umbonella. Desbayes, Coq. Fos. p. 52, pi. 7, figs. 18, 19. 



Shell transversely ovate, thick, and globose, with a short 

 beak in front ; umbones large, recurved, and prominent ; sur- 

 face with strong scaleriform stri;i.». 



Found in the London Clay at Bracklesbam. 



5. Corbula gigantea. — Gigantic Corbula, pi. XCI. f. 38. 

 C. gigantea. Sowerby, III. p. 13, pi. 209, figs. 5, 6, 7. 

 Gibbose, transversely oblong ; anterior side produced and 



recurved ; posterior and part of the front side furnished with 

 short spines, placed in longitudinal rows ; surface concentric- 

 ally furrowed near the beaks ; this side very concave, and 

 separated by an obscure ridge. 



Young shells gibbose, with very equal ribs between furrows, beiog 

 broadest in the middle, and narrowing towards the sides. 



The Greensand, Hants and Blackdown. 



6. Corbula globosa. — Globular Corbula, pi. XCI. fig. 19. 



C.glohosa. Sowerby, III. p. 14, pi. 209, fig. 3. 



Globular, smooth ; its thickness equal to its length ; ante- 

 rior side of the larger valve produced into a lip, and obtuse in 

 front ; posterior side round, and the front obtuse ; beaks equal. 



London Clay, Highgate and Waudsworth. 



7. Corbula elegans. — The Elegant Corbula, pi. XCI. 

 figs. 23, 24. 



C. elegans. Sowerby, VI. p. 139, pi. 572, fig. 1. 



Sub-globular ; right valve more convex than the left ; con- 

 centrically sulcated ; posterior side somewhat produced, smooth, 

 and truncated ; left valve sub-triangular, smooth ; the beak 

 of the sulcated valve is somewhat curved, and destitute of 

 a beak. 



Greensand, Blackdown. 



8. CoRBDLA stbiatula. — The Minutely Striated Corbula, 

 pi. XCI. figs. 21, 22. 



C. striatula. Sowerby, VI. p. 139, pi. 572, figs. 2, 3. 

 Slightly ovate, ventricose ; valves nearly equal ; minutely 

 striated ; beak long, straight, and doubly channeled internally. 

 In the Gault, Folkstone. 



9. Cobbula rotundata. — The Rounded Corbula, pi. XCI. 

 fig. 31. 



C, rotundata. Sowerby, VI. p. 140, pi. 572, fig. 4. 



Gibbose, ovate, sides nearly equal, the posterior one slightly 

 truncated ; beaks produced ; concentrically furrowed ; sides 

 nearly equal. 



The Red Crag, Sutton ; Pleistocene Marine, Ayr and 

 Forth ; and Norwich Crag, Bramerton. 



10. Corbula obscura. — Obscure Corbula, pi. XCI. f. 25. 



C. obscura. Geo. Tr. 2d Ser. II. p. 320. Sowerby, VI. 

 p. 140, pi. 572, fig. 5. 



Gibbose, ovate, smooth ; posterior side flattened. 

 Inferior Oolite, Brora, Sutherlandshire. 



11. Corbula nitida. — Shining Corbula, pi. XCI. fig. 29. 

 C. nitida. Sowerby, IV. p. 85, p!. 362, figs. 1, 2, 3. 

 Gibbose, ovate, sub-trigonal, equilateral ; anterior side 



truncated, smooth, and shining ; valves nearly equal ; beak 

 produced and rather inflated. 



This species hardly exceeds three-tenths of an inch. 



Upper Marl, Isle of Wight. 



12. Corbula cuspidata. — The Pointed Corbula, pi. XCI. 

 figs. 13, 14. 



C. cuspidata, Sowerby, IV. p. 85, pi. 362, figs. 4, 5, 6. 



Tumid, transversely oblong, sub-equilateral ; anterior side 

 carinated and pointed ; lower margin of left valve expanded 

 and inflated, bending over the margin of the opposite valve ; 

 disk somewhat rugged ; length not quite two-eighths of an 

 inch ; breadth two and a-half eighths. 



Upper Marl, Colwell and Whiteclifl" Bay. 



13. Corbula complanata. — The Flattened Corbula, pi. 

 XCI. fig. 30. 



C. complanata. Sowerby, p. 86, pi. 362, figs. 7, 8. 



Depressed, transversely ovate, elongated, its length about 

 half its width ; anterior side smaller than the posterior ; sub- 

 truncated, and defined by an obtuse ridge ; posterior portion 

 of the right valve exceedingly depressed and thickened ; sur- 

 face with seven or eight transverse furrows, the interstices be- 

 ing smooth J left valve most convex, and enveloping the 

 right. 



Red Crag, Sutton. 



14. Corbula pisum. — The Pea-shaped Corbula, pi. XCI. 

 fig. 20. 



C. pisum. Sovperby, III. p. 15, pi. 209, fig. 4. 



Sub-globular ; anterior side slightly truncated ; margin of 

 one valve produced ; beaks unequal, that of the larger valve 

 very prominent and ventricose ; surface concentrically fur- 

 rowed ; margin extending beyond the anterior side of the larger 

 valve and a portion of the front. 



The London Clay, Barton. 



15. Corbula revoluta. — The Revolved Corbula, pi. XCI. 

 figs. 16, 17, 18. 



C. revoluta. Sowerby, III. 16, pi. 209, figs. 8, 9, 10. 



Tumid, transversely oblong, its width double its length ; 

 anterior side produced and truncated, with a keel running to 

 the beak ; margin of larger valve prominent and inflected ; 

 beaks unequal ; transversely furrowed ; larger valve envelop- 

 ing the edge of the lesser one, and with the front expanding, 

 and revolving inwards. 



The London Clay, Barton, and Heme Bay. 



A variety of this species has fewer and deeper furrows, with the ante- 

 rior side somewhat pointed. 



16. Corbula curtansata. — The Shortened Corbula, pi. 

 XCI. fig. 4. 



C. curtansata. Phillips, Geo. York, I. pi. 3, fig. 27. 



Transverse ; anterior side large and rounded ; posteriorly 

 acuminated ; beaks almost central ; surface smooth, with well- 

 marked lines of growth ; basal line triangular. 



The Coral Rag, Malton, and South Cave, Yorkshire- 



