2 



BRITISH FOSSILS. 



tubercles 9 in each row, bordered with very minute lateral tubercles, and 

 divided by a conspicuous miliary furrow ; spines very much flattened. 



Locality. — Rare in the Upper Chalk of Kent and Sussex. 



4. C. tiara, Ag., An. Sc. Nat., 1846, p. 351. Morris's Cat., 2nd ed., 

 p. 75. Cidaris tiara, Hagenow. Phymosoma saxatile, Desor, Syn, p. 87. 



** Nearly equally depressed above and below. A range of very incon- 

 spicuous secondary tubercles on the base, upon each side of the interambu- 

 lacral areas, but disappearing at the circumference. Miliary tubercles very 

 few. Pores reduplicate." — Desor. 



This species was introduced into the English catalogues on the 

 authority of M. Agassiz himself, but the specimen so named by 

 Prof. Forbes appears to be only a casual variety of C. Konigi. 

 M. Desor's description answers best to C. coroUare. He revives 

 the name given to an urchin imbedded in flint, by Parkinson, who 

 identified it with the living Echinus saxatilis. He also quotes 

 Mantell's figure, which would be equally indeterminable, but that 

 the specimen is preserved in the British Museum, and proves to be 

 C. spatuliferum. 

 Locality, — Upper Chalk, Gravesend, Kent. 



5. C. corollare (Park.), Forbes, in Morris's Cat., 2nd ed., p. 75. 



Body circular, depressed, lat. 12, alt. 4 lines (usually smaller), base 

 concave, oral opening small (lat. 4 lines), apical opening large, pentangular 

 (lat. 5-5J lines) ; pores crowded near the summit ; primary tubercles 

 small, with plain areolae ; interambulacral tubercles 9 in a row, with small 

 irregular marginal and wide granular interspaces, becoming smooth 

 above; ambulacral tubercles 9-1 1, tapering to either end. Spines long, 

 slender, and spatulate, one-fourth longer than the diameter of the test. 



Locality. — Very common in the Upper Chalk of Kent, and not un- 

 frequently with the spines in situ. 



6. C. Wether elli, Forbes, in Morris's Cat., 2nd ed., p. 7. 



Like C. spatuliferum ; but the interambulacral tubercles bordered by pro- 

 minent miliary granules, and by small lateral tubercles on the under 

 surface only. 



The unique typical example, partly imbedded in flint, was obtained 

 at Gravesend, and presented to the Museum of Practical Geology 

 by N. T. Wetherell, Esq., F.R.S. In the absence of further evi- 

 dence, it can only be considered a variety of the last species. 



Locality. — Upper Chalk, Gravesend. 



7. C. simplex, Forbes, in Morris's Cat., 2nd ed. p. 77. 



Body small, convex, lat. 9, alt. A\ lines ; base concave, mouth small ; 

 apical opening pentangular ; primary tubercles prominent at the circum- 

 ference, small and inconspicuous above ; areolae radiated, large and nearly 

 confluent at the middle, very small above, and separated by a wide finely 



